This is becoming slightly more common knowledge than it used to be, but for everyone who hasn't heard, a significant number of colour printers in the US (exactly which ones is not known, but it includes those made by Xerox and Canon) imprint a secret code into every sheet of paper they print, encoding the serial number of the printer used (enabling the government to track its owner) and the date and time it was printed. A research team working for the Electronic Frontier Foundation has cracked this code (link to main article, with pictures of the code and details on how to read it here).

Am I the only one who finds this slightly disturbing?

I'm actually rather surprized that full disclosure by the printer company to the consumer isn't required by law, it should be. Perhaps I'll contact my Senators about this...I don't mind that they do it, but the companies selling these printers should be required to tell the consumers what is happening.

That seems very unsettling to me. The idea may have had some innocent reason like tracking reports in a crowded office, but it seems like you could misuse it. Some stores keep track of the serial numbers of the products they sell, so you could track down someone who doesn't want to be found based on the serial number in the paper. For example, if you send an unsigned letter of anger and disapproval to the government, they could find out who you are and where you live. Seems very creepy and "Big Brother" -ish.Some people may find the numbers useful, but the companies should have to inform consumers that their printers do that in a clear disclaimer printed obviously on the box and the printer itself.

Crivens, that's black-helicopter-tastic. If I wish a document I print to be attributable to me I'll damn well put my name on it. The potential for identifying, and maintaining a list of, people who are 'politically unreliable' is staggering, and few legitimate uses spring to mind.

Having one of the printers listed as doing this (Epson Aculaser C900) I shall be printing a test sheet to ascertain whether it is also the case for European models, and will report back with my findings.

Good plan, Fuzz.

The ostensible use for this is to track down counterfeiters, I understand.

Which doesn't strike me as being a very good excuse. Counterfeit money made with a laser printer simply wouldn't look or feel right, and that's the only form of counterfeiting Xerox claim to be interested in. A layer of toner fused to paper is thick enough to feel easily, and the printing method used has nothing to do with many of the security features used for currency. Not to mention that the increasing number of currencies now printed on, at least partially, plastic substrates pretty much rules out high temperature processes such as laser printing in many areas.

I've run off a couple of test sheets, and am now looking for my blue LEDs to light them up.

I am disturbed, but not surprised. Most things now are traceable--our phone calls, emails, our DNA. It would be a behemoth job for the government to constantly keep tabs on every citizen, but quite frankly, if they're keen on watching you, the means are completely at their disposal. I suspect there are plenty of ways we can be traced and watched, a number of which we are unaware of. I don't like it and I believe we should be informed, but I doubt they will of their own motivation. Alas for muckrakers, eh?

It's not necessarily a very new idea though. The letters on manual typewriters all wear at minutely different rates, developing to a point where a letter typed on a machine will be as distinctive as a fingerprint. The same has been true of electronic printers that have distinctive minor faults in the hed alignments. Such things have been used as evidence in ransom cases to prove who sent a note. Certainly this is a lot more overt, but I'm not really very surprised, and (strangely for me) I'm not very worried by it either. I've always considered my things to be traceable anyway!

Well, I did it, I contacted my representative in Congress (Rodney P. Frelinghuysen) and one of my senators (Frank Lautenberg), because Corzine is currently running for Governor, and probably won't actually do anything. I doubt any of them will do anything, but at least I can feel like a good citizen.

Out of interest, does this mean that it would be a really good idea to invest in shares of companies that produce yellow ink?