The kind that thinks communism is the same as nazism and thinks communism is when the government does things.
I hate liberal brain worms.
They seriously do as much damage to the left as fascists by punching to the left and spreading capitalist anti-left propaganda. They overall weaken leftism and help fascism.
We need more left unity, folks. Fash ain't gonna bash themselves. 
I usually call them infantile and ignore them, because they are babies. An anti-imperialist anarchist is a tankie to them.