Facebook has stepped up to defend itself from Yahoo’s recent accusation of violating ten of its patents. On March 12, 2012, Yahoo filed a lawsuit in US District Court for the Northern District of California against Facebook, claiming that its alleged innovations in messaging, news feed generation, social commenting, advertising display, and privacy controls are actually based on Yahoo’s patented social networking technology.

Unlike Google – which settled its litigation with Yahoo prior to its initial public offering (IPO) for one percent of the company’s worth – Facebook refused to settle and took the risk of proceeding with the lawsuit despite its IPO scheduled in May. As part of its defense, Facebook countersued Yahoo, including ten claims of its own for patent infringement, each in response to a patent infringement claim made by Yahoo.

One claim, though, Facebook fails to tackle: the one relating to ownership of the protocol that enables seamless communication between email and instant messaging users. As for other nine infringement claims, Facebook refutes all the patent infringement claims patent by patent. For example, Facebook refutes the infringement claim on Yahoo’s “Dynamic Page Generator” patent with its patent on the news feed and claims that Yahoo Flicker website copies Facebook’s news feed content. It is notable that Facebook’s responsesto Yahoo’s patent infringement claims are more specific in nature than the ones made by Yahoo. In case its other responses fail to offset Yahoo’s attacks, Facebook also added a claim that Yahoo’s Flickr copied Facebook’s photo tagging technology.

It is interesting to note how aggressively Facebook defends itself with its counterclaims. Facebook has been moving at a rapid speed to acquire more patents from other owners perhaps to fight claims against its lack of patents compared to its size. In fact, in at least one case, and perhaps several, the patents asserted were acquired after Yahoo provoked Facebook by accusing the company of patent infringement. At the same time, company has also signaled that it is averse to patent lawsuits by claiming it countersued Yahoo only “in response to Yahoo’s short-sighted decision to attack one of its partners and prioritize litigation over innovation” and is likely to drop the lawsuit if Yahoo does.