If it comes from 1 IP you could try blocking it with an "iptables" command, but you will need SSH/telnet access for that, or maybe your host can help you.
<a href="http://www.whois.sc" target="_blank">www.whois.sc</a> lookup a few random IP's. The chances are they are SE bots and real vistors. Google indexes our forum like crazy and we experience a similar thing to what you are, although not a 200 user count ....