You could print a canary token with deda_create_dots. Add a URL that won't otherwise be visited in the history of the universe to an endpoint that notifies you that someone has you under a microscope. 301 to rickroll.

I'm not that paranoid or naughty, but I give it to you for your next spy novel.

Reportedly, OpenPrinter will not have these dots by default. I did wonder if this omission would cause them issues. As I understand it, the dots are not mandated by law.