Which is why arguing with them is pointless. They're not listening.
If you tell a Zeitgeist zealot that all they're doing is restating Marxist rhetoric, they simply deny it and move on. There is no arguing with someone who will not listen. Come up with two or three obvious ways they're wrong, present those any time they post, and move on.
Anyone who will be convinced by the rhetoric isn't going to listen to the realism of an-cap anyway. If they ever come back and _ask_, then they are ready to listen.
I have a socialist friend and everytime it ends the same way, I keep getting sucked in though. I will remember to just walk away next time. What a shame...