incrediBILL - 3:29 am on Apr 26, 2012 (gmt 0)
You're probably right, they're probably trying to bypass filters.
If you're going to spoof to bypass filters it seems more logical to use a browser user agent than Googlebot which can be easily authenticated and fakes blocked in real-time. Although browser agents coming from hosting locations is a policy violation for many bot blockers so they would deny access to that as well.
Sounds like they're just going to have to live with getting blocked in a few places now doesn't it? :)