Googlebot and others

So what do these bots actually do? Whose are they and how did they possibly get a username and password? It's a little annoying to think that these bots are out there gathering passwords and usernames from all the really good paysites that I can never seem to afford.

Fear not, the bots don't actually have a username and password, it's just my software determining who they are based on their 'user agent' .. they 'see' the site as a guest who isn't logged in would see it. As to what they do, the vast majority (but not all) of them index the site in some way, usually to provide search engine data.