Annoying little buggers.
A spambot is a piece of software that registers at a message board for the purposes of advertising or (in the case of the Chan attacks on the Cafe) annoyance. It can usually easily be identified by its random-looking name (often a jumble of letters and numbers), its country , or the website it advertises (which is also usually identified by country.)
Prior to the conversion of the Acorn Cafe to PHPBB version 3, spambots were a constant nuisance. However, the patrons at the Cafe devised a way where they could have some use: by inventing ingenious methods of destroying them on a specially created thread on the Cafe Foyer forum. The newly-identified spambots would be the subject of various forms of destruction, including but not limited to being fired on by all kinds of firearms, being dragged at high speed behind a Ford pickup truck, and used for target practice by both starships and battleships. The popularity of this thread (and the number of spambots) was impressive, as the thread reached 33 pages and 466 posts before dieing out. In addition, it provided an excellent way to notify the moderators of the Acorn Cafe of which accounts needed to be deleted.
This thread has more or less died out since the conversion to PHPBBv3 has virtually eliminated the threat of another "spambot invasion." For now, at least.
Spambots are currently the subject of a 3D animation that Severe Weather Eddie is working on. (And he swears it will be finished someday. No, really...)