Helpfully the law already disagrees. That Xerox machine tampers with the printed result, leaving a faint signature that is meant to help detect forgeries. You know, for when users copy things that are actually illegal to copy. Xerox machine (and every other printer sold today) literally leaves a paper trail to trace it back to them.
i believe only color printers are known to have this functionality, and it’s typically used for detecting counterfeit, not for enforcing copyright