# License plate readers and privacy? **URL:** \ **Category:** Factual Questions\ **Created:** [October 2, 2019, 4:44pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159 "2019-10-02T16:44:09Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![JoseB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/joseb/32/1530_2.png) [@JoseB](https://boards.straightdope.com/u/JoseB)\ **Post date:** [October 3, 2019, 5:53pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/21 "2019-10-03T17:53:32Z")
> [@Spiderman](#): > > This was one of the fears when EZ-Pass came out. They know the distance between any two toll points. They know what time you entered & exited. Assuming no traffic jams nor your stopping at a rest stop, they can very easily calculate your average speed. They said they wouldn’t issue tickets based on this to allay fears. Of course when do you expect a politician to keep their word, especially when there’s money in it for them, even if not directly into their pockets fines would free up other funds for other uses so they don’t look bad by raising taxes (as much). Heh… something like this has been implemented already for years in the highways here: “trajectcontrole”. At a certain point on the highway your car triggers a photo; after X km of highway (and at the exits between the start and end points of the trajectcontrole) there is another camera. The system has automated number plate reading; it knows at what time you entered the controlled stretch of highway and at what time you leave it, and calculates your average speed. Officially, only the data of the vehicles that break the speed limit are kept for further processing, all information on law-abiding vehicles being destroyed as soon as the calculation has been made and it has been seen that the speed was OK, but well… Dunno whether to believe that or not 😛 ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 3, 2019, 7:42pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/22 "2019-10-03T19:42:30Z")
> [@ftg](#): > > SCOTUS’s take on recording tags with cameras and computers is that it’s merely a faster way of doing it than by people with pens and pads. Since they consider the latter to be perfectly okay, what difference does it make legally if you go higher tech? Nothing for a one-time deal. Tracking a car’s position over multiples day over a long period of time is considered a search (IIRC) under the 4th Amendment ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 3, 2019, 8:19pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/23 "2019-10-03T20:19:56Z")
> [@Joey\_P](#): > > Except the police aren’t following people around all day. They’re scanning all the plates in a given area. They _might_ be able to put that information together in a way that would give them a rough idea as to your whereabouts over the course of a day or week, but it’s a far cry from stalking. When a city the size of LA or NYC had a couple of license plate readers - maybe. When they become as common as traffic cameras, and all that data is collected - it’s not a long stretch to realize that cameras placed at busy intersections and choke points, plus a giant database of all such readings, results in a “connect the dots” display of where and when a vehicle travelled. I read something about HOA’s setting up LPR’s to see who visits the neighbourhood and when, how long they stay (with fun privacy implications like “why is that car always there? He’s not on the occupant list. Are you violating the family-only tenant rule?” Similarly security at large shopping malls have them to scan the parking lot for assorted issues - abnormally long parking times, abandoned or stolen cars… Also suggestions that such private LPRs could add their data to a law enforcement network database. just because California dumps the data after 2 years doesn’t mean others who read the database are obliged to do so with data they download. Plates were intended for (a) visually signalling the licensing is complied with and (b) verifying ownership during traffic stops or witnessed offenses and (c) allowing a means of assigning parking and other unoccupied traffic violations to be attached to a vehicle. The only thing that comes close to the LPR issue is (2), and that was not anticipated to morph into a means to constantly track anyone anytime. The big issue is the database. IIRC, the whole issue with NSA record collection - vaguely recall some court cases over this - the government needed probably cause to collect data like who you called, when how long etc. (“pen register” data, I think) Collecting innocent citizens’ data for no valid reason (probable cause) was a violation of the 4th amendment. Reminds me of the story of the medieval bishop directing a siege of a French town. When they were going to overrun it and kill the heretic Cathars, he was asked how they could tell the heretics from the good Catholics. His reply “Kill them all, God will sort them out.” ---
**Author:** ![Patch](https://avatars.discourse-cdn.com/v4/letter/p/a183cd/32.png) [@Patch](https://boards.straightdope.com/u/Patch)\ **Post date:** [October 3, 2019, 9:59pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/24 "2019-10-03T21:59:09Z")
Circumstances have pulled me from the office for a few days, so there are some questions and clarifications I have for folks at work who know more about the system than I. Yes, ‘stalking’ is a bit of a reach, but it certainly is tracking me nonetheless, especially when they are recording what’s parked in front of my house and in my driveway. And I know for a fact one of the ways this is used is, “hey, we arrested Bob on drug charges. Where does he hang out? Oh, we see his car parked at 123 Elm Street. Who lives there? Let’s run background on them and see if they have a criminal history. Where do we see that person’s car and who are they visiting?” Great, so because it’s easier for Bob to park across the street in front of 124 Elm Street, now that person is being looked at. This isn’t about looking for stolen cars, it’s about tracking the populace. ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [October 4, 2019, 5:11am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/25 "2019-10-04T05:11:38Z")
> [@dstarfire](#): > > I also seem to recall a case where the court (not SCOTUS) ruled that LPR readers feeding a centralized database was effectively the same as placing a tracker on the vehicle, and that such a thing was impermissible even when their was no physical interaction with or physical trespass of the vehicle. You may be thinking of [This](https://www.caranddriver.com/news/a27243732/parking-chalk-constitution-court-ruling/). Up until rather recently (last 2 decades anyway) anyone could get the data of license plates. In my state it was 2 bucks to find out who owned what and where they lived. It wasn’t until the stalker laws and other such laws took effect that knocked that out. Some states even sold CD’s with every plate and cross reference names. In many places private security ad investigators can still legally obtain such info. How’s that helping everyones paranoia? > [@Patch](#): > > But if I were to follow someone around all day, every day, recording where they were traveling, that would be stalking. No it isn’t. What do you think private detectives get paid to do? In most states there are certain elements that have to exist before it’s stalking. ---
**Author:** ![nightshadea](https://avatars.discourse-cdn.com/v4/letter/n/7ba0ec/32.png) [@nightshadea](https://boards.straightdope.com/u/nightshadea)\ **Post date:** [October 4, 2019, 6:37am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/26 "2019-10-04T06:37:19Z")
I know that when the city of Oakland writes a traffic ticket they take a picture of the plates When my aunt had a car they sent her a parking ticket by mail … Now we live 800 miles SE of oak/SF I called and disputed the ticket and after giving him the license plate number and a few minutes of discussion he took the ticket processing number and said " wait a few seconds I’m looking at the picture of the plate now… Oh yeah, it’s supposed to be xyx9 instead of xyz 8" typed some stuff in and changed it and said, "you might get a late notice or two just toss em " ---
**Author:** ![bengangmo](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@bengangmo](https://boards.straightdope.com/u/bengangmo)\ **Post date:** [October 4, 2019, 6:55am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/27 "2019-10-04T06:55:33Z")
> [@Patch](#): > > Circumstances have pulled me from the office for a few days, so there are some questions and clarifications I have for folks at work who know more about the system than I. > > Yes, ‘stalking’ is a bit of a reach, but it certainly is tracking me nonetheless, especially when they are recording what’s parked in front of my house and in my driveway. And I know for a fact one of the ways this is used is, “hey, we arrested Bob on drug charges. Where does he hang out? Oh, we see his car parked at 123 Elm Street. Who lives there? Let’s run background on them and see if they have a criminal history. Where do we see that person’s car and who are they visiting?” Great, so because it’s easier for Bob to park across the street in front of 124 Elm Street, now that person is being looked at. This isn’t about looking for stolen cars, it’s about tracking the populace. It doesn’t seem to me that this is a good argument. Compiling a database of where a drug dealer goes and being able to catch more of his customers? So cry me a river. Or to put it another way… Track a known kiddy diddler by his license plate, and catch others that are like minded. What’s more of a concern is the possibility of non criminal behaviour being found out and used against people. E.g. affairs, participating in a swingers event, etcetc ---
**Author:** ![pkbites](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pkbites/32/204_2.png) [@pkbites](https://boards.straightdope.com/u/pkbites)\ **Post date:** [October 4, 2019, 7:26am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/28 "2019-10-04T07:26:56Z")
> [@nightshadea](#): > > I know that when the city of Oakland writes a traffic ticket they take a picture of the plates Most of the hand held ticket printers have cameras. Our current ones can take up to 10 pics per cite. But I don’t think that’s what the OP is concerned about. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [October 4, 2019, 9:30am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/29 "2019-10-04T09:30:24Z")
I guess that you guys would not be too happy over here in the UK, where plates are scanned everywhere you go. I go to the supermarket and they get scanned on the way in and on the way out because there is a three-hour restriction on free parking. All filling stations scan the plates of every car to combat drive-offs; Transport for London scan my plates when I enter and leave the congestion zone and many sensitive areas scan the plates of every passing vehicle. Most police cars are now fitted with ANPR so if the pull me over, they already know if the car is taxed and insured, and who owns it. There is a lot more; some of which is public knowledge and some not, and the UK has some of the most surveillance cameras per head in the developed world. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 4, 2019, 5:35pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/30 "2019-10-04T17:35:23Z")
Pictures or video of license plates were pretty common for a decade or three. IIRC, the freeway tollbooths etc. would take pictures for catching toll evaders. The big shift is when a camera can feed a character recognition device and add a license plate (by text) to a database complete with location and time info with no human intervention. This takes things a step further - with sufficient coverage, you now get the “connect the dots” capability to track a car anytime, any place. Plus the manufacturers that sell these devices to private citizens might include the capability (optional or not) to update a central company database with the details, adding to the level of detail available to anyone who can finagle their way onto the database. It’s the same shift as when GPS trackers became available. When police had to allocate a human to watch and follow someone, it was only done in serious circumstances. When it’s simply a matter of catching the car unattended and slapping a device in the wheel well or under the bumper and then collecting 24-7 data real time, for an unlimited number of people - that’s a whole different matter. The police did not need a warrant to tail someone - they do to GPS them. there has to be a reasonable suspicion or whatever the threshold is for a warrant. Doing the same thing by putting a series of cameras along the way is no different - except the Supreme Court decision, IIRC, hinged on the act of actually trespassing and touching the subject’s vehicle. But basically, there’s a privacy issue in having a long history of the actions of innocent people immediately accessible to police without a warrant, or to private third parties with who knows what restrictions, if any. The same can be said of facial recognition, with the proviso that it is less reliable than LPR tech. (I note that Hong Kong is planning to ban facemasks to combat civil unrest) Of course, the next question will be - how reliable is LRP tech, and does the system also store photos (for verification)? Do we take a computer’s word for it that it did not make a mistake reading, with possible life-altering repercussions? As usual, the law has not caught up with technology. (I’m reminded of the story about some kids who took a photo of a teacher’s license plate, printed out life-size copies and taped them over their car plate and drove through a number of red-light cameras.) ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [October 4, 2019, 7:04pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/31 "2019-10-04T19:04:56Z")
I started a thread about this years ago when I first encountered these police vehicles because the car wash I operated at the time had a fleet account with a local PD and they were wondering if the cars equipped with the cameras could go through the wash or not (no they couldn’t). Here it is: [So Cops Have These Things Now... - Mundane Pointless Stuff I Must Share (MPSIMS) - Straight Dope Message Board](https://boards.straightdope.com/sdmb/showthread.php?t=597387) Those cops are using them to catch outstanding warrants tied to the plates. They just sit there all day, then suddenly swoop out and pull someone over and arrest them. It’s a little creepy, but understandable given that we submit to the idea that driving is a government-sponsored privilege. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [October 4, 2019, 8:40pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/32 "2019-10-04T20:40:55Z")
> [@Spiderman](#): > > This was one of the fears when EZ-Pass came out. They know the distance between any two toll points. They know what time you entered & exited. Assuming no traffic jams nor your stopping at a rest stop, they can very easily calculate your average speed. They said they wouldn’t issue tickets based on this to allay fears. Of course when do you expect a politician to keep their word, especially when there’s money in it for them, even if not directly into their pockets fines would free up other funds for other uses so they don’t look bad by raising taxes (as much). And yet EZPass has been in NY for something like 26 years, and I’ve never heard of someone getting a ticket via hte above scenario ( And I’ve often been in cars that would have gotten a ticket if they were doing this) Speed cameras, however are another story - and as far as I know, they don’t even need to read your license plate at the moment of taking the photo. ---
**Author:** ![Patch](https://avatars.discourse-cdn.com/v4/letter/p/a183cd/32.png) [@Patch](https://boards.straightdope.com/u/Patch)\ **Post date:** [October 7, 2019, 5:46pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/33 "2019-10-07T17:46:20Z")
> [@Machine\_Elf](#): > > So the information is stored for years at a _maximum._ > > There are a lot of other rules in that document regarding how the data may be used, who may use it, how it is to be safeguarded, and so on. Did some follow-up this morning on it. The data that’s collected is distributed to a private company, which is a clearing house for a large number of license plate readers nationwide. Retention policies of Sacramento at that point are irrelevant, as the data is in private hands. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 7, 2019, 5:52pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/34 "2019-10-07T17:52:01Z")
> [@bengangmo](#): > > It doesn’t seem to me that this is a good argument. > Compiling a database of where a drug dealer goes and being able to catch more of his customers? So cry me a river. > Or to put it another way… > Track a known kiddy diddler by his license plate, and catch others that are like minded. > What’s more of a concern is the possibility of non criminal behaviour being found out and used against people. > E.g. affairs, participating in a swingers event, etcetc It’s for things like “reasonable suspicion” and “probable cause” that I’m glad I live in the United States. I wouldn’t want to live in the police state “catch the criminals no matter the cost to the innocent” that you live in. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 7, 2019, 6:12pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/35 "2019-10-07T18:12:09Z")
> [@Saint\_Cad](#): > > It’s for things like “reasonable suspicion” and “probable cause” that I’m glad I live in the United States. I wouldn’t want to live in the police state “catch the criminals no matter the cost to the innocent” that you live in. Exactly - oddly enough, it’s not restricted to drug dealers and pedophiles. EVERYONE is caught up in the database. Too many coincidences and you get dragged down to police HQ despite a lack on non-circumstantial evidence. The “I have nothing to hide” mentality is very misguided. Do you want your travel activities available to anyone willing to pay? Your boss, to see if you left early too often? Maybe the cops will assemble a list of cars parked at venues that serve liquor, and put a yellow flag on anyone who shows up on the list more than twice? See which way patrons go home and wait there until their reader goes “bing!” and pull you over for a breathalyzer? Does the “I have nothing to hide” mentality extend to allowing the police to pull you over whenever you are driving after 9PM and pass a police car because you were designated driver a few times? Do you want your insurance rates to go up because you drove to the bar or a restaurant that serves alcohol? (And those are only some of the scenarios I can imagine. Privacy used to be nice. ) ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [October 7, 2019, 7:57pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/36 "2019-10-07T19:57:27Z")
> [@md2000](#): > > The “I have nothing to hide” mentality is very misguided. I wonder how many of the “I have nothing to hide” crowd would willing allow cops to search their house, car and person at anytime - even if they’re not there. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [October 7, 2019, 8:21pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/37 "2019-10-07T20:21:48Z")
> [@Joey\_P](#): > > Except the police aren’t following people around all day. They’re scanning all the plates in a given area. They _might_ be able to put that information together in a way that would give them a rough idea as to your whereabouts over the course of a day or week, but it’s a far cry from stalking. Police here, anyhow, are scanning plates as they patrol, looking for plates associated with warrants and stolen cars. So it isn’t just in limited areas. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [October 7, 2019, 8:50pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/38 "2019-10-07T20:50:36Z")
> [@Patch](#): > > Retention policies of Sacramento at that point are irrelevant, as the data is in private hands. No, they should be contractually obligated to the retention policies of the ‘owner’ of that data. They _should_ be deleting it after two years if that was Calif wants. If they’re not doing such they are in breach of the appropriate section(s) of the contract & potentially subject to some penalty. Probably just financial but potentially criminal as well. I don’t know the specifics as to their contract or Calif law to be able to give more detailed answers. ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [October 8, 2019, 1:38am UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/39 "2019-10-08T01:38:41Z")
You have no reasonable expectation of privacy when you drive around on the streets with a big identification number on the car. The computers are simply doing what a policeman with a notebook could do, and have done for decades. It is a change of scale, but not of type. ---
**Author:** ![RioRico](https://avatars.discourse-cdn.com/v4/letter/r/f04885/32.png) [@RioRico](https://boards.straightdope.com/u/RioRico)\ **Post date:** [October 8, 2019, 5:24pm UTC](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159/40 "2019-10-08T17:24:27Z")
Privacy? It’s an illusion. We are tracked everywhere, our communications monitored, our habits, locales, spending, associates, fetishes et al recorded and backed-up forever. Data is immortal. We are known and can’t hide. Motor vehicle ownership and usage are state-granted privileges, not divine rights. Drive by the rules you can’t get away with violating. Yes, a state can do whatever it wants with any motor vehicle data… within their legal bounds. In states resembling democracies, if you don’t like those legal bounds, you can vote for change. But licence-plate scans are old and trivial. Modern factory-built motor vehicles are computers that roll. On-board systems record vehicle data. I predict that soon, licensed vehicles’ data will be legally required to be uploaded regularly to state servers for real-time analysis. Your every infraction will be known, and appropriate citations issued and fines levied automatically. Maybe ten bucks per mph over the limit per ten seconds. THAT would be a great fund-raiser! LPRs are only a token of our ubiquitous-surveillance future. Forget privacy. [Previous page](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159.md?page=1) [Next page](https://boards.straightdope.com/t/license-plate-readers-and-privacy/841159.md?page=3)