Seemingly, when colour laser printers print pages, they may include tiny dots, almost invisible to the naked eye, which can be used by the US Secret Service to track down counterfeiters. It has emerged that this code has been cracked.

"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 EFF Staff Technologist Seth David Schoen.