Who here has heard about the HP printer thing?

Ok, so I just started college for IT and one of my teachers started talking about something with HP printers... he said that HP could find out if a page was printed from any HP printer and if it was, then exactly what printer it was. It had something to do with microprinting something into the first or last letter of the last or first page or blah... I dunno.

Anyone hear anything about this?

http://digitallifetv.com/blogs/digitallifetv/default.aspx (watch episode 11)
http://www.eff.org/Privacy/printers/index.php

Start reading....it does exist.

http://www.eff.org/Privacy/printers/docucolor/

edit: beat me

I do know there are some "hidden" printing done on color copy machine and high end laser printer (mainly in the form of 6x6 or 8x8 yellow dots that are easily visible under blue lights) mainly to track down counterfiets to the owner of the printer. I don't think it's applied to customer level printers where the quality of potional counterfiets are often questionable enough not to get past sharp eyed cashiers.