Flamebait
Flamebait (aka TrollBait) is a message posted to an Internet discussion group, such as a newsgroup or a mailing list, with the intent of provoking an angry response (a "flame"). Various motives or explanations can be sought for this puzzling behavior; the desire for attention and the desire for entertainment at others' expense are two leading motives.
It should be pointed out that, of course, it is often hard to determine who is really responsible for the degradation of a reasonable discussion into a flamewar. Someone who posts a contrary opinion in a strongly focused discussion forum may be easily labeled a "baiter", "flamer" or "troll". Therefore, it seems especially important to make the rules and focus of a discussion forum public to avoid misconceptions about its accepted use.
The conclusion to a flamewar precipitated by flamebait is usually determined by recourse to Godwin's law.
See also Internet troll, Social software.