Amazon makes that money in about 6 seconds. I don't think they would even bother to threaten them, but that's just my opinion. Maybe that's the motivation behind the scam as well?

Yeah, this is way more likely than paying 600. Amazon lawyers are a very very brutish sort. I've worked with them.

Another possibility is that the site is trying to give the impression big companies are paying so when they go after small fry it'll go easier on them.

They could always switch it to feedback about the river.