Hypothetical Cash Tracking, Other Spying Paranoia

Here’s a way that cash could be used to track you, based on some basic assumptions.

  1. Money is scanned (OCR, etc.) at the bank, and the serial numbers are reported to a central database.
  2. Identity of depositor is maintained with bills $20 and higher.
  3. The serial numbers on the bills are kept track of when the money is stacked in the ATM and the cashier drawers.
  4. Bills are given to consumers sequentially from ATMs and bank cashiers.

Joe consumer gets a stack of $20 bills at the ATM. He goes various places and spends the cash. When the retail stores in question get around to depositing that cash in the bank, it gets scanned again as coming from that retailer.

With this system and a little data mining, you could trivially place watches on a list of people to see where they spend their cash. Though there would be massive amounts of information to move around and process, if there’s a relatively small number of people to check serial numbers against, it could be manageable with relatively modest computer systems.

OK, so the fact that you shopped at Circle K and got a tank of gas, went to a particular grocery store where you presumably bought groceries isn’t all that exciting.

Of course, if you traveled cross-country stopping to pick up gas and grab a bite to eat with cash hoping to remain anonymous, your direction of travel could be monitored. Not in real-time mind you, but within a few days of the money changing hands, according to when cash pick-ups are made from various points, and how long before the cash is processed again.

So if you really want privacy from your cash, you’ll need to launder it (i.e. swap it with someone else for funds at least one step removed from a bank), or presumably storing your cash for a certain amount of time before spending it. There’s only so much data you can keep on the billions of bills in circulation no matter how big a computer system you have, so it would only keep information for a certain window of time.

What’s more interesting is those ‘Grocery Discount Club’ cards. These are potentially marvelously evil. You save your 10%, but now your complete purchase has your phone number, name and address associated with it. ALL of your purchases. Of course, using a debit or credit card to make the same transaction will similarly finger you. So the theory goes, various retail chains sell copies of the database to interested parties. Among them are health and life insurance providers. With a little bit of clever automated data mining, they can determine if you buy smokes, junk food, lots of red meat, etc. So they can ‘know’ if you have unhealthy eating habits, and can ‘adjust your rates’ accordingly.

The amount of data the credit companies have about you is downright awful.

Similarly, census microdata extracts are supposed to be ‘scrubbed’ so the identities of people can’t be determined, but using ever more subtle mining methods with ever more computational power behind it, census data has been ‘cracked’ to reveal individual identities. Of course, governments have used census data in scandalous things for as long as censuses have been taken. When the government its self abuses census data, there is no privacy at all. The Nazis had very accurate census data, and you know what they used it for. U.S. census data was used to track down Japanese Americans to send to internment camps, and more recently on Muslim Americans.

Here’s another slightly creepy one. A web spider service that looks for blog and forum posts to find negative opinions about your products. A fine use for such a system would be a company like Microsoft that wants to defend the reputation of its shoddy, bug-ridden products. You need to find a place to send your shills where they can do the most good.

Hello there, Pingnak. Just a reminder: a link to the column you’re commenting on is appreciated. This is the one : http://www.straightdope.com/classics/a5_030.html

Ah, OK, thanks!

A word on Grocery Discount Cards: They work as intended without an associated name/phone number. Just don’t fill out the form. They also work as a single use card:

Cashier: “Do you have a Saver’s card with us?”
Me: “Why, no, I don’t! Can I get one please?”
Cashier: “Here you go, just fill out this form and drop it in the mail!”
Me: “Okay!”
Drop card in trash on the way out, repeat on every visit to the store.

Your basic assumptions regarding cash tracking is based on the premise that banks would actually be able to keep track of the serial numbers of bills stacked in their cash drawers and ATMs. What about if someone deposits (as I often did when I was running a small business) hundreds of dollars in twenties, tens, fives and ones. These bills would be placed on top of the stacks in the cashier’s drawer, and then passed on to the next person making a withdrawal or cashing a check. Do you think they would take the time to note the serial numbers of all those bills and enter them into some sort of database while there are other customers waiting behind me?

Very interesting! But consider this: If the government wanted to spy on you, it could just tap your phones, requisition your ISP records, and track your movements… without asking any judge for a warrant. Likewise, enforcement regarding whatever regulations exist for buying and selling data is completely absent.

The problem is that for all the shouts of “privacy,” we have really no philosophical underpinning beneath the idea. No one knows why they want privacy except that they do.

And no one wants to write laws to honor it except in a superficial, placating way. Because there just doesn’t appear a rational reason.

From time to time I find a key chain size card in the store parking lot. I have three of them that I rotate through.

Don’t forget, money you hand to a cashier, will probably be handed back to the next customer, and the system wouldn’t work.

Each clerk/teller would have a combination scanner/bill dispenser. The scanner/dispenser would keep track of who the money was from or who it was going to.

But I think you’re right about the time anyway. I think at present generalized optical scanning just isn’t reliable enough, so the clerk/teller would have to manually enter the serial numbers on a large percentage of bills.

That, of course, could change.

Any bills larger than $20 they receive go into a slot in most stores, especially convenience stores. If their $20 drawer is full, they put the $20s in the slot, too. Watch them. Most places only keep cash to make change. This is because someone comes in to rob them, they can clear out $300 from the register, but not the thousands in the safe, below it.

Banks already scan notes as a matter of course. They have a complete record of the serial numbers, because if there’s a fire or a theft or whatever, they want that cash back. The numbers are precisely printed and scanner-friendly already. Have been that way for decades.

Nowadays you see ever more of those self-checkouts being adopted by various big box stores. Often the only check stand open. Walmart, Home Despot, Lowez, etc. You feed those bills in one at a time, face up, just so. Tell me these machines couldn’t scan the bills. Tell me they don’t already. Can you be sure?
Another cute piece of news. Tell me these rocket scientists wouldn’t be interested in tracking cash transactions.

Boy, I dunno. I mark bills and enter them at the WheresGeorge.com website, so I’ve looked at the serial numbers of thousands of bills. the green overprint of the numbers (and the seal on the right side) bounces all over the place in relation to the black ink of the rest of the face-side. Now, the black shifts around in relation to the bill’s margins so it might be that moving about and the green is actually stationary to the edges; I havent actually measured that.

This is true, but I know from experience working as a register monkey that you’ll get at least one dillhole per shift who doesn’t have anything smaller than a fifty or hundred for his two dollar purchase. A couple of those will effectively clear your drawer out of twenties.