That's the way it goes.  Initially rational folks will try to argue with a troll, only to realize they aren't getting anywhere.  All they're doing is feeding him more trollcarbs to fuel his trolltrolley.  Once those folks stop, the troll finds others to instigate, who'll then take their turn feeding the beast.  On and on it goes, and we're all guilty having taken our turns.  Hell, I even tried to talk some sense into him recently.

From now on, I'm just going to stand back and watch.