What caught my eye in this article was this phrase: "Today an ISIS supporter might adopt a pseudonym to harass a critical journalist on Twitter, or a right-win

What caught my eye in this article was this phrase: "Today an ISIS supporter might adopt a pseudonym to harass a critical journalist on Twitter, or a right-wing agitator in the United States might smear demonstrations against police brutality by posing as a thieving, violent protester." Are there really such "right-wing agitators" out there or it's just a hypothetical case? Any investigations, perhaps? Or is it just a usual political struggle? I noticed that the most favored comment also was against the conservative party.