How do you know that? Civil rights and protest movements in general have traditionally not relied on social media or even digital communication of any sort. Couldn't the mechanisms once employed to organize activists still work today? The answer is yes, they can. I know for a fact the Baptist church down the street from me participated in organizing many of the protests in my city this summer.
I'm not so sure about that. That kind of policy would definitely put the breaks on uncoordinated viral peer-to-peer spread, but that just might lead to resurgence of coordinating organizations acting as clearinghouses for such things.
That could be good, at least in places with decent civil liberties, since I believe broadcast speech is bit like code: it's better when there's some peer review and sanity checks before it's distributed.
People often retort that no one cares about decentralization, well we're going to find out if that's really true over the rest of the decade.