I've just installed a modification to the forum software (created by some clever person, not me) that gives a breakdown of the visitors to the forum on the "Who's Online" page. This is the page you see if you click on the link just under the People Online heading near the bottom of the main page.
In particular, it shows who is a real guest, and who is a robot (a.k.a. spider) from one of the search engines.
If you feel a bit queasy about these creatures reading your posts on the forum, you needn't. It's just search engine computers collecting data for their indexes of the Web. On the other hand, if you feel a bit queasy about the possibility that anybody in the whole world who has an Internet connection might stumble on one of your posts via a search engine, then you probably ought to bear that in mind when you're sending messages. It might feel like we're in our own little private clubhouse here, but we're actually putting our comments into the public arena.