Trolling is defined by Herring as baiting and luring others into pointless and time-consuming discussions.
4 criteria of trolls:
1. Appearance of outward sincerity.
2. Posts designed to incite anger or "flames"
3. Posts designed to waste everybody's time with useless argument
4. Desperate desire for attention, any attention at all
Recognize them, don't engage and put 'em on your ignore list where they belong. Feed a troll and you're just encouraging their attention-seeking.