The Electronic Frontier Foundation, a consumer privacy and digital rights organization, alleged Tuesday that there are codes embedded in printouts made by some color laser printers that can be used to track the origin of a printed document.

The codes are ostensibly a part of anti-counterfeiting measures developed by government agencies to curb the creation of fake currency but could have serious implications for consumer privacy, according to privacy advocates.

A research team led by the EFF said that it has broken the code behind tiny tracking dots that some color laser printers secretly hide in every document.

“We’ve found that the dots from at least one line of printers encode the date and time your document was printed, as well as the serial number of the printer,” said Seth David Schoen, staff technologist at EFF.