# Postage stamp conspiracy theory **URL:** \ **Category:** Factual Questions\ **Created:** [December 17, 2019, 10:34pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007 "2019-12-17T22:34:12Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 17, 2019, 10:34pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/1 "2019-12-17T22:34:12Z")
I think this is the first conspiracy theory I have started. I purchased some stamps from the self service machine which prints the stamps as you order them. They have one of those coded information fields with patterns of black and white dots. Is it possible this field contains a transaction ID that ties that particular stamp to your debit card information and can easily be linked to the surveillance cameras? THEY would then be able to find out who purchased that stamp if need be. Dennis ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 17, 2019, 11:03pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/2 "2019-12-17T23:03:47Z")
Sure, it’s possible. ---
**Author:** ![AlsoNamedBort](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alsonamedbort/32/3213_2.png) [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)\ **Post date:** [December 17, 2019, 11:03pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/3 "2019-12-17T23:03:58Z")
Could it? Certainly, that data could be encoded into a qr code. Does it? [No.](https://www.frederickding.com/posts/2016/01/whats-in-that-usps-pc-postage-barcode-032643/) ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 17, 2019, 11:43pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/4 "2019-12-17T23:43:59Z")
Well, the ones from the machine are much different from that standard square design. And if you read through the analysis there are unknowns and certificate numbers, etc. Also the ones you linked to use a lot of fields for how much postage has been printed by that machine and remaining funds available, etc. None of that is needed for machines in the post office itself. That’s where they hide the transaction ID. Dennis ---
**Author:** ![Kimera757](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kimera757/32/3765_2.png) [@Kimera757](https://boards.straightdope.com/u/Kimera757)\ **Post date:** [December 17, 2019, 11:55pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/5 "2019-12-17T23:55:50Z")
> [@mixdenny](#): > > I think this is the first conspiracy theory I have started. > > I purchased some stamps from the self service machine which prints the stamps as you order them. They have one of those coded information fields with patterns of black and white dots. Is it possible this field contains a transaction ID that ties that particular stamp to your debit card information and can easily be linked to the surveillance cameras? THEY would then be able to find out who purchased that stamp if need be. > > Dennis Half right, I guess. First… yes, it’s probably possible. I don’t think that’s being done as that’s a complete waste of time, however. Most likely they just want a way of knowing how many stamps were sold. There’s various patterns on the food I buy, and I know nobody cares about that. (Except for my loyalty program.) The amount of info those dots can capture is pretty limited, probably limited info such as Sold in this Store on this Date. If you were buying stamps with RFID, this would be more likely. Usually “random” numbers end in a check digit, so you won’t see something convenient such as Stamp 1001, Stamp 1002, Stamp 1003, more like Stamp 100001, Stamp 100007, Stamp 100012, and so forth. As for the second, only the cameras in the store have a chance of capturing your face. The dots won’t help the post office communicate with any other video cameras. That information would be deleted after a period of time, not necessarily for privacy reasons, but simply because information takes space, or at least energy, to store. (The NSA is overwhelmed by all the information they’re taking in, even though much of that info is analyzed by computer. The post office is less powerful, and would simply look at the return address and look at the postmark on the envelope itself.) If someone wants to know who mailed a letter… they can use fingerprint powder. I doubt most people write while wearing latex gloves. I would find it difficult to seal an envelope without leaving fingerprints, or DNA, on the envelope. (I don’t use saliva, but there would still be DNA evidence.) There’s also handwriting analysis, which I think is less useful, but it could help catch someone who writes while wearing latex gloves. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 17, 2019, 11:58pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/6 "2019-12-17T23:58:33Z")
If you can find an image of the exact type of code you are talking about, we could decode it to see what is there. (That does not rule out steganographic microdots, of course.) ---
**Author:** ![Carryon](https://avatars.discourse-cdn.com/v4/letter/c/9fc29f/32.png) [@Carryon](https://boards.straightdope.com/u/Carryon)\ **Post date:** [December 18, 2019, 12:20am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/7 "2019-12-18T00:20:47Z")
Yes, they are identifiers. I can’t find the specific story but a man was caught harassing someone through the mail, because he bought stamps from the machine, rather than the clerks, and the police were able to tie the codes from the machine stamps to his card ---
**Author:** ![Carryon](https://avatars.discourse-cdn.com/v4/letter/c/9fc29f/32.png) [@Carryon](https://boards.straightdope.com/u/Carryon)\ **Post date:** [December 18, 2019, 12:25am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/8 "2019-12-18T00:25:02Z")
Here is a story about how the police caught someone using a post office self serve kiosk > **[Wannabe Serial Killer Taunted Cops With Zodiac-Like Letters](https://www.thedailybeast.com/daniel-alfred-gallegos-taunted-cops-every-time-i-see-young-beautiful-femalesi-want-to-strangle-them)** > > This summer a series of letters shocked law enforcement across the country, detailing how a man planned to maim and murder women. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 18, 2019, 12:36am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/9 "2019-12-18T00:36:16Z")
I knew It! Here is the type of stamp I am talking about: > **[USPS self-service kiosks dispensing new Flag design](https://www.linns.com/news/us-stamps-postal-history/2018/october/usps-self-service-kiosks-dispensing-new-flag-design.html)** > > The image shows only a detail of a fluttering 50-star flag, with 13 stars showing entirely or partially, along with segments of eight red or white stripes. Dennis ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 18, 2019, 1:04am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/10 "2019-12-18T01:04:09Z")
> [@mixdenny](#): > > I knew It! Here is the type of stamp I am talking about: > > [USPS self-service kiosks dispensing new Flag design](https://www.linns.com/news/us-stamps-postal-history/2018/october/usps-self-service-kiosks-dispensing-new-flag-design.html) > > Dennis That’s interesting. It does appear to be some kind of serial number, at least that’s what it looks like, so they definitely know exactly where and when that stamp was sold. ---
**Author:** ![Manlob](https://avatars.discourse-cdn.com/v4/letter/m/96bed5/32.png) [@Manlob](https://boards.straightdope.com/u/Manlob)\ **Post date:** [December 18, 2019, 1:11am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/11 "2019-12-18T01:11:13Z")
When the stamp machine at my post office started requiring credit card and only dispensed custom printed stamps with ID codes, I suspected the same thing. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [December 18, 2019, 1:11am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/12 "2019-12-18T01:11:56Z")
> [@DPRK](#): > > That’s interesting. It does appear to be some kind of serial number, at least that’s what it looks like, so they definitely know exactly where and when that stamp was sold. Well, there would have to be, wouldn’t there? Otherwise, you could just copy them yourself. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [December 18, 2019, 1:13am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/13 "2019-12-18T01:13:24Z")
> [@mixdenny](#): > > I knew It! Here is the type of stamp I am talking about: > > [USPS self-service kiosks dispensing new Flag design](https://www.linns.com/news/us-stamps-postal-history/2018/october/usps-self-service-kiosks-dispensing-new-flag-design.html) > > Dennis According to my barcode/QR reading app, that stamp says “unknown encoding.” ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 18, 2019, 1:32am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/14 "2019-12-18T01:32:41Z")
Are you reading it as Data Matrix? One still has to decipher the IBI code but the barcode itself should decode, producing a string of binary data. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 18, 2019, 1:57am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/15 "2019-12-18T01:57:07Z")
I found the information. Nothing about linking the stamp to a the purchaser’s card info but that could be as simple as the machine itself keeping a log. “The first four characters in the number string identify the dispensing kiosk, and the next five show the date, with a single digit (8) for the year (2018), followed by four digits representing the month and date. The final six digits tell the time of day, with two digits each for hour, minute and seconds.” Dennis ---
**Author:** ![Lord\_Feldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lord_feldon/32/341_2.png) [@Lord\_Feldon](https://boards.straightdope.com/u/Lord_Feldon)\ **Post date:** [December 18, 2019, 6:57am UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/16 "2019-12-18T06:57:08Z")
If it includes the kiosk, date, and time, I think that would have to be enough to allow a determined investigation to link the stamps to a card transaction. ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [December 18, 2019, 12:12pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/17 "2019-12-18T12:12:32Z")
> [@Lord\_Feldon](#): > > If it includes the kiosk, date, and time, I think that would have to be enough to allow a determined investigation to link the stamps to a card transaction. Heck, that’s enough information for Barney Fife to link the stamps to a specific transaction / buyer. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [December 18, 2019, 1:02pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/18 "2019-12-18T13:02:09Z")
I don’t understand. If you use a debit/credit card with your name on it … then they know who you are. If you use such a stamp later to do something bad then the info on the stamp plus looking up the sales record pegs you. No camera/scanning needed. To preserve anonymity (for whistleblower purposes or similar legal reasons), then you have to use an anonymous card like a CC gift card. Which means buying it with some anonymous payment (e.g., cash) in a place that isn’t recording you. (Plus avoiding being recorded when you buy the stamp.) Even the serial numbers on the cash might have been recorded by the ATM that dispensed them. You might want to go several cycles deep to obscure the trail. It’s all levels, Jerry. ---
**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\ **Post date:** [December 18, 2019, 1:19pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/19 "2019-12-18T13:19:25Z")
I just have to note how people seem to get their dander up if they suspect the government is somehow keeping tabs on them, but could not care less that a business might do the same thing and also profit off doing so. I find the latter infinitely more reprehensible. ---
**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:** [December 18, 2019, 1:37pm UTC](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007/20 "2019-12-18T13:37:49Z")
Get used to it… We live in a surveillance society and it will get more so in the coming years. Cameras on street corners, HMA’s recording all cars in their areas, cameras in shops and offices. As we all use cards more and more, so we leave a trail of data about what we buy and where. I just looked at my CC statement (online of course) and it would not take a genius to see that I have been visiting someone in hospital this week, and at what times. (Costa Coffee if you are interested). Criminals still manage to hide their identities, or at least the sensible ones do, but the Man on the Clapham Omnibus, doesn’t really have a chance, so he may as well relax and go with the flow. Do I mind that Tesco or Amazon know what I spend my hard-earned on - no, not really. Do I care that my bank knows that I am visiting a hospital, again, no. Frankly, there is enough to worry about in this world without concerning myself with Big Brother. [Next page](https://boards.straightdope.com/t/postage-stamp-conspiracy-theory/845007.md?page=2)