My assumption is everything everywhere on the internet is already assumed to be fair game for spying, scraping, training, whatever.

At this point the interests seem more about serving than gathering information - hence the political games to control specific platforms now.

Conan? Days Gone? Waterskis?

If we are talking platforms, then the employees of that platform. If we are talking federation, then the community and groups leading the communities. The consequences are the same as always. Bans for rule violations, and the freedom we all share to use or not use these platforms.

Content moderators per community guidelines. Why is this so hard?

Why is this not as simple as adding a setting button for moderation of hateful content? The user can decide to filter it out.