Who knows? There are all sorts of hacks that search for personal info - credit card #'s, etc. If you look at Anonymous and see 0 seconds, that's probably the one. It would be nice if the moderator could check out who the Anonymous is, as it seems to be a constant presence. I just noticed his name down below. I'll contact him and ask him to take a look.
Anonymous are just guest users that haven't registered. They could be real people or bots that are indexing the site to support their search engine. Just means that they aren't logged into the site.
JB