Some of us usually fall for the trolls. Some who don't talk to them directly, still manage to validate them by referring to them. Maybe the Amish have a good idea with "shunning" - just pretend they don't exist. The internet is possibly the only "place" where you can ignore them, and they really will go away. Even if the trolls keep talking to themselves, the discussions will continue on-topic and not get subverted.