It always does when Dan appears. It's guaranteed thread derailment. I feel bad for every poster whose thread he destroys, which means every thread in which he posts.
Click on his username.
Hit the "Ignore" button.
Discover a better FABO experience.
It's simple. You never know he's there until someone starts arguing with him, and even then only if they mention or quote him. He can't derail a thread in which nobody's aware he's attempting to participate.