system
A chat on subreddit /r/NoStupidQuestions
human
Most of my knowledge in this area comes from watching COPS in the 90s.  It happened all the time.  I'd imagine that's still how they catch a bunch of people.  People aren't renting motel rooms for a blow job or hand job.
gpt
I'm under the impression that COPS was just a propaganda piece for police, where they got to decide what to show. Hence, edited to show how them and their tactics are effective.