Ever get the feeling that your technology is spying on you? Turns out, it is, but probably not in the way you’re thinking!

In the 1980s color printers were becoming popular in homes and the government was worried that people could use them to counterfeit money. Because of this, the Xerox corporation developed the Machine Identification Code to track printed documents. Using a series of practically invisible yellow dots arranged in a binary code, your documents could be traced by the time, date, and printer serial number hidden on every page.

This code was used successfully to track counterfeiters and the public didn’t become aware until 2004, almost 20 years later! So the next time someone talks about their phone listening to them, share this little story about their printer.

Today we also celebrate: National Shortbread Day, National Bean Day, and National Cuddle Up Day.