This should be the case for ALL social networks. You have the right of free speech, but your voice doesn't necessarily have equal grounds with every other.

"Twitter’s founders always talk about the service as a kind of public square, where everyone should be able to have a more or less unfettered voice. That’s a misguided analogy, because it misses the nuances of the real world.

Even a real public square imposes limits on how people can behave. Sure, the sign-wielding crazy guy is free to stand up on a crate and spout his nonsense — but you’re free to ignore him, and if you do, he’s not allowed to marshal all his acolytes (or to invent new ones) to follow and harass you. More than that, in the real world, we have many ways of determining who is worth listening to and who isn’t; there are body language, ways of speaking, ways of dressing and an overall history — an earned reputation that determines a person’s place in the community."