There’s no reason to panic, but this is a little unnerving. The EFF has found that all printers produce teeny tiny yellow dots on each and every piece of paper that passes through them. But what they can’t figure out is why.
These super small dots are so small, in fact, they can’t really be seen with the naked eye. In order to see them, you’ll need to either view them under a microscope or under a blue light. Blue light turns the yellow dots black, making them show up better like in the photo above.
EFF has determined these dots indicate the printer model from which a document was printed. It can also include information like the time and date it was printed. It’s all pretty strange. It seems the government asked the printer companies to do this and they complied. But is this legal? Who knows. But now I want to check out some documents under blue light. Check out the video below and visit Seeing Yellow for more information.