Tiny dots produced by some laser printers are a secret code that can allow the government to track down counterfeiters, a new study concludes. Secret codes in printers may allow tracking ...

According to experts, several printer companies quietly encode the serial number and the manufacturing code of their colour laser printers and colour copiers on every document those machines produce.

They’re almost invisible but contain a hidden code – and now their presence on a leaked document has sparked speculation about their usefulness to FBI investigators.