Earlier quoted context omitted.
What's "extremist"? Dabiq?[1] Stormfront? Donald Trump? The National Rifle Association? Fox News I think its pretty simple. If a given group has ever claimed responsibility for, expressed the intention to commit, or publicly praised, a terrorist act against civilians, that's an extremist group. Whatever can be done to block their communications with the rest of the world should be done. It's no mystery as to who they…
People protesting against austerity and gentrification have broken windows of banks and stores. Is this terrorism since in the end civilians own those? If it is where do you draw the line on censorship of the people who want the same things but were never involved in those crimes against property?
No, it's "terrorism" because the purpose of "terrorism" laws is to crush domestic political dissent rather than to actually ward off foreign ideological militants.