PSA: "wtf rito u cant ban me i has mah FREEDOM OF SPEECH!!1!1!1!2!2!2!!!"
First of all, legal freedom of speech doesn't even apply to this. That solely applies to the government, to which it states they cannot prosecute you or try to punish you for speaking out against the government. (Outside of slander and libel which would be illegal as it falls under defamation.)
Second of all, social freedom of speech is just that. Freedom of speech. It's not "Freedom to be an Asshole". It is also not "Freedom from Consequences of Speech".
So before you start trying to scream at Riot that it's illegal for them to ban you and that you're going to sue them, please actually learn what you're talking about. Or, don't. Seeing trolls try to use this excuse is always a good laugh.