I mean they do dictate by dictats (e.g. youtubes guidelines) and curate by moderation so that does not make them a public forum (which would be only subject to

I mean they do dictate by dictats (e.g. youtubes guidelines) and curate by moderation so that does not make them a public forum (which would be only subject to the law, not the mayor's arbitrary demands), nor do they claim to be a public forum. They don't actually produce the content, but in the end they dictate what people see . It's not much different