Unbelievable, I just discovered that my printer was spying me !
When you print on a color laser printer, it’s likely that you are also printing a pattern of invisible yellow dots. These marks exist to allow the printer companies and governments to track and identify you — presumably as a way to combat money counterfeiting. When one person asked his printer manufacturer about turning off the tracking dots, Secret Service agents showed up at his door several days later.
The global explanation and the list of affected printers is here : www.seeingyellow.com
Something to see with 9/11 event ?
UPDATE : here are some examples from a printer I can play with :
- original paper without any post filter : you can zoom but you won’t see anything
- paper with yellow post filter : you can zoom and you will see the famous yellow dots
- paper with yellow + b&w filter : you can see the grid of spying dots without zoom !
Instead of trying to remove this protection from your printer, why not devellop a driver who would jam it, by printting thousand of “fake” yellow dots, depending of the model’s sheme.