Facebook has bought WhoGlue’s networking tool and the stakes of its 10 shareholders, including Siemens AG, said WhoGlue Founder Jason Hardebeck. WhoGlue filed suit against Facebook in September 2009, claiming that the social network “violated a patent awarded to WhoGlue in 2007 for an “information management system’ to control personal information as human networks and technology increasingly mesh.”

WhoGlue specializes in designing private social networks, for member groups, such as alumni associations. Hardebeck sees a future where public social networks interact with private networks more seamlessly. WhoGlue’s first interaction with Facebook occurred in September 2009 when it sued the company.

As part of the deal, Hardebeck ended up buying back some assets, trademarks and customer relationships from Facebook, and formed a new company, WhoGlue LLC, that can continue to operate the same business.

Financial details of the transaction were not disclosed.