Contact the peertube host. If they choose to leave it up, you can contact law enforcement / a court who can make a genuine judgement as to the legality of the content and take up approrpriate enforcement.
Probably the same as email curation. If a spammer is caught, you ban them from your server. If other servers notice that spam is coming from a particular server, those servers disconnect from that server.
But Politics and Porn? These taboo subjects will be hard to deal with in a federated environment.
With Federated networks you can block an entire domain, so if you don’t like seeing it you don’t have to- but if you do want to talk about taboo subjects you can in your own space.
If your server builds a reputation as being a nanny state, your users will often exodus and go to another site.
As such, the status-quo eventually creates the loosest set of rules. See 4chan, Reddit, and other social networks. The fewer the rules, the bigger the userbase. Any effort to tamp down based on moral concerns leads to huge controversies (ie: /r/Jailbait, /r/TheFappening, and other controversial reddits)
It takes an extraordinary amount of effort to clamp down on a taboo subject. The "free speech" advocates are incredibly strong. Even "obviously wrong" subreddits like /r/CreepShots took an absurd amount of Drama before things got resolved.
