I own a forum www.FootballDiscussion.net, i was going through the whos online list, and well, this is what showed up: This is the first time this has happened, i browse the online list very often, theres always one Google Bot
Googlebot is generated from tens of data centers and they are regularly crawling the web all the time. No wonder your site has been hit by the bots coming from a variety of IP addresses.
I don't understand the problem. Ten isn't a big number when considering how many crawlers can be on large forums (well, any website for that matter) at a time. This is something you should be no less than supportive of. Would you rather have your content crawled at a much lower rate or perhaps not at all?
Don't forget, Google has services like Translate and Adsense which can trigger requests to your server from Google as well. For instance look at that screenshot, notice a couple of them are "posting" ?