I think that's our best option for avoiding oppression. Case in point, video of George Floyd. If we had widespread public (by the public) surveillance, I think people would feel safer. If someone is "disappeared," hopefully there'd be evidence that the ACLU could pursue.

The "extraordinary rendition" program the CIA was using to disappear terror suspects into places they could be tortured was discovered in part by airplane-spotting hobbyists. Because planes are extremely hard to hide, and there are people who watch airports to see what takes off and lands for fun.

When they pooled their data, they were the first group to notice the military had started running flights to and from locations they didn't normally fly, and it didn't take much investigative journalism after that to discover those planes were carrying people.

Do you have any sources for people who are interested in reading more on that?

Extraordinary rendition is a good search phrase.