A "bot" is an automated program (robot) that searches the Internet and catalogs the information it finds for search engines like Yahoo and Google and MSN (bots I've seen here). They are also known as web crawlers.
I'm a bit surprised that they actually identify themselves the way they do here on the BBB, but I suppose that's a good thing. The BBB keeps track of its users, many of which are not logged on and are noted as "guests" in the notations at the bottom of the page.
--I know what I like--