Actually, there never really was a “Free Speech Movement,” other than using that name. It was started in Berkeley in the ’60s by radicals. I’m sufficiently jaded that I can’t imagine them having supported Barry Goldwater’s freedom of speech. He may or may not have needed special protection to speak back then, but he certainly would today, and groups like this would be the reason.
In any case, it would be funny to think that it ends with Milo Yiannopoulos. His own Berkeley speech was cancelled last night due to a riot.
The linked article blames “black bloc” anarchists. That’s where a group wears masks and black clothing to make it more difficult for the police to identify and prosecute.