Gangs and Guilds in MMOs, again

A long while ago I posted about some research that showed that gangs and guilds seemed to have mathematical characteristics in common.  A few days ago, I got this sent to me by someone at the department of CS and Engineering at the University of Minnesota:

Hi,

I saw a previous post on your blog about similarities between MMOs and street gangs. Me and my research group (VWO) recently published a paper which contradicts the previous results. We thought you may find it of interest.

Thanks, Muhammad

The blog post about the paper can be found here, with some conclusions, and you can also read the pre-print PDF of the paper. It looks like this is based on the the same set of Everquest II data that many researchers have been using for a while now — I am unsurprised to see Dmitri Williams credited.