Some printers now print yellow tracking dots so that law enforcement agencies can track documents back to the printer that produced them.

Aside from the legal/privacy issues I think it really is bad that the printer makers have not disclosed this information. The EFF: List of Printers Which Do or Don’t Print Tracking Dots is trying to fill the information gap. Except for Tektronix and Xerox (who admit to including the “feature”) it currently seems that none of the other manufacturers are forthcoming. Shame on them.