Whenever you print a page on your color laser printer, the printer automatically prints a nearly-invisible watermark that provides the serial number of that printer to law enforcement authorities.
Doesn't it make you feel safe to know that everything printed on your laser printer can be traced to you? This helps foil counterfeiters, of course. And maybe it could be used to detect terrorists. Or people who voted Democratic, or printed things in Arabic or Hebrew.
Of course, our government wouldn't do something like that, any more than American soldiers would torture prisoners or hold citizens without trial.
Doesn't this make you feel all secure?