The Banhammer is the name for a certain tool used by admins and moderators of various sites. Said to be a weapon of the internet steeped in legend and lore, it is in fact, the software that instantly bans you off if you have been breaking rules and engaging in massive displays of faggotry. W.T. Snacks usually is seen with one.
The degrees of banhammering are varied, though it is known that the maximum judgement inflicted usually goes as far as permanent global IP track banning.
If you are the victim of a banhammering, it's usually justified or wielded by a constipated and vindictive shit.