Facebook has been sued by Rembrandt Social Medial, LP for patent infringement. Rembrandt Social Media doesn’t run a social media site, but was created by Rembrandt 
IP Management, LLC, with the family of the deceased inventor of the patents and the inventor’s company Aduna. According to the complaint Rembrant works “to help inventors and patent owners, who often do not have the requisite capital or expertise, enforce their rights against companies that use their inventions without paying for them.” In other words, Rembrandt is a Non-Practicing Entity – what some people call a patent troll.
Rembrandt alleges infringement of two U.S. patents: the ‘362 Patent and the ‘316 Patent. Both patents have filing dates back to 1998. The ‘316 Patent discloses a personalized web diary that can be shared with other users. The ‘362 Patent relates to the features such as the “Like” and “Share” buttons.
Beyond the patent infringement allegations, the complaint also alleges a potential conflict of interest for the patent attorneys who prosecuted the cases. According to Rembrandt, the law firm that represented the inventor in prosecuting the patents began prosecuting applications for Facebook in 2008. The law firm then continued to represent both Facebook and Aduna until July of 2012 when the law firm terminated its relationship with Aduna.
The case probably looks worse for the law firm than it really is. The Aduna patents issued in 2003 and the law firm’s involvement was likely limited to the docketing and and paying of maintenance fees. While it can’t be determined from the complaint, the law firm may have only discovered the relationship of the subject matter in June 2012, when Facebook acquired a patent in which the ‘362 Patent was cited as prior art.
There isn’t enough information in the complaint to gauge the severity of the conflict, or if there really is one. It does, however, show the potential for “subject matter conflicts” to develop into direct conflicts among clients.