Can one patent a community detection method?

One can patent a community detection method? What?

Will somebody please explain this to me?

Update: The patent apparently belongs to Huberman and Wu (familiar names, and now I know what community detection method it's based on). You can find the details here. In the 6 years since the patent was filed and when it was rewarded (in January 2010), the method has become completely out of date. Still, WTF?