Facebook may not resemble a likely victim of patent trolls but a couple of companies still wish to probe its vulnerability when pounded with patent suits. Mekiki Co Ltd, which runs the Japanese social networking site Samurai Social Network, has filed a patent infringement suit against Facebook, claiming that it infringes three of its patents related to a “human relationships registering system."

From what we understand, the Japanese firm has called into question the use of the very axe that helps break the ice on social networks like Facebook: friendship requests. Mekiki was awarded US Patent #6,879,985 in 2005 for, among other things, “a message communicator configured to communicate a first message from one member to another member and configured to communicate a respective response to the first message from the another member to the one member, the response establishing a relationship between the one member and the another member.”

Boston-based Tele-Publishing Inc also believes that certain Facebook features contravene one of its patents. US Patent #6,253,216 was awarded to Tele-Publishing way back in 2001 and deals with the “method and apparatus” used for serving a personal page. The subject of its patent infringement claim appears to be Facebook’s privacy feature, which protects all the dazzling nymphets and the handsome hunks from the prying eyes of cyber stalkers. In fact, most contemporary social networks let their users specify who gets to view what.