In short, I support people creating “safe spaces” as a shield by exercising their freedom of association to organize themselves into mutually supporting communities, run according to their own norms. But not everyone imagines “safe spaces” like that. Some use the concept of “safe spaces” as a sword, wielded to annex public spaces and demand that people within those spaces conform to their private norms. That’s not freedom of association. That’s rank thuggery, a sort of ideological manifest destiny. It’s the difference between saying “I shouldn’t be forced to go to a talk by this controversial figure” and “this controversial figure should not be allowed to speak at my school.”