Reminds me of the old days. When X11 was not correctly secured, i.e., most of the time, it was possible to remotely login to someone‘s system, take a screenshot of :0 and display it on :0. :0 is the local display, so the computer seemed to be frozen.
https://en.wikipedia.org/wiki/Cadence_SKILL
I thought I see Cadence Skill here on HN.