A counterfeit detection tool on color printers are raising concerns that it may violate a user’s privacy.

From USA Today:

More manufacturers are outfitting greater numbers of laser printers with technology that leaves microscopic yellow dots on each printed page to identify the printer’s serial number — and ultimately, you, says the San Francisco-based Electronic Frontier Foundation, one of the leading watchdogs of electronic privacy.

The technology has been around for years, but the declining price of laser printers and the increasing number of models with this feature is causing renewed concerns.

The dots, invisible to the naked eye, can be seen using a blue LED light and are used by authorities such as the Secret Service to investigate counterfeit bills made with laser printers, says Lorelei Pagano, director of the Central Bank Counterfeit Deterrence Group.

Privacy advocates worry that the little-known technology could ensnare political dissidents, whistle-blowers or anyone who prints materials that authorities want to track.