Pixelique

With the help of a microscope and a trusty blue LED (see, those things are useful for something other than mods), the EFF researchers were able to reveal a grid of yellow dots that provide information about the date the printout was made, as well as the printer’s serial number. Is your printer tracking you? If you’ve got a DocuColor and a microscope (or a powerful magnifying glass), you can decrypt your dots via the EFF’s web site. If you’ve got another printer, you can send in paper samples for them to add to their research database. In the meantime, don’t assume that anonymous letter blowing the whistle on your employer’s nefarious deeds or a politician’s leak of a CIA agent’s name can’t be traced back to you. (source: Engadget)