> or "only existing in the mind of a paranoid person" did actually happen.

This reminds me of the 2020 case where a union organizer thought there was a spy camera inside a utility pole outside his house. It was in a conspiracy subreddit, so it seemed like the deranged ramblings of a ravingly-paranoid stranger. But they found the addresses of the IP cams and had plenty of evidence to corroborate it.

Now, Flock cameras are just normal.

I think the 2020s will be defined by this trend. "Things which only existed in the minds of a paranoid person" becoming normal parts of daily life.