couple things.

• they're in an anarchist group

I have no problems with anarchists, just specifically groups of anarchists. kind of negates the whole "anarchist" thing.

• they were promoting intelligent interaction with trolls and authoritarians to combat the spread of their influence

if everyone ignored them, then their influence would stop. There's no reason to interact with either.

ultimately their ideas only feed the people they are arguing against. this leads me to believe this person is either a troll or a fool. considering they're a member of an anarchist group I assumed they're a troll and not an anarchist.