1. Your printer probably puts a secret code into everything you print (not just money-like things) with the time and a serial number of the printer. [0]
2. Windows and MacOS constantly sends the serial-numbers of your connected devices back to the mothership. [1][2]
3. So when you print out a flyer that somehow annoys the regime, they read out the serial number, then call a buddy at Microsoft/Apple.
4. Now there are thugs knocking at your door to talk about how your picture was criminally mean to Dear Leader.
[0] https://www.eff.org/pages/list-printers-which-do-or-do-not-d...