Almost every time a company is dragged into court, the process becomes a drain on its resources and isn’t great for PR (no matter how ridiculous the claims).  It’s perhaps understandable, then, that Facebook has acquired all of Friendster’s social networking patents and patent applications for a reported $40 million.

Although everything was kept hush-hush at the time, late yesterday, Owen Thomas was able to point to a United States Patent and Trademark Office page documenting the move.  It proves that seven patents and 11 patent applications changed hands in mid-May, when Facebook must have been negotiating its Facebook Credits deal with Friendster owner MOL Global.

As for what the patents cover, the first handful of titles are "Multimedia aggregation in an online social network," "Proximity search methods using tiles to represent geographical zones," "Method for sharing relationship information stored in a social network database with third party databases," "Compatibility scoring of users in a social network," and "System and method for managing connections in an online social network."

Then the last couple are "Method of inducing content uploads in a social network" and "System, method and apparatus for connecting users in an online computer system based on their relationships within social networks."

Meanwhile, it was Liz Gannes who was able to pinpoint the purchase price at $40 million.

This represents an interesting move on Facebook’s part.  Again, as a purely defensive measure, it makes a certain amount of sense.  But owning these patents could also help the company go after Google if it becomes too much of a threat in the social space, or Facebook might be putting itself on firmer legal ground in preparation for an IPO.