Yahoo escalates legal fight with Facebook, adds two patents to suit

Yahoo is escalating the hostilities and the stakes in its increasingly acrimonious patent battle with Facebook.

In papers filed in San Francisco federal court Friday, the Internet search company expanded its lawsuit against Facebook to include two more charges of intellectual property theft. It now claims Facebook is infringing on 12, rather than 10, of Yahoo’s patents.

“Today’s filing underscores the breadth of Facebook’s violation of Yahoo’s intellectual property,” a Yahoo spokesman said in an emailed statement.

Yahoo filed the suit against Facebook last month. The lawsuit raised eyebrows in Silicon Valley, where companies often use patents to defend themselves, but not to go after each other so as to avoid stifling innovation. Facebook countersued, claiming Yahoo was infringing on its patents.

Yahoo denied claims Friday that it was infringing on 10 of Facebook’s patents and accused Facebook of engaging in unfair tactics. It said Facebook violated an agreement between the two companies to notify each other of possible patent infringements before going to court.

“We remain perplexed by Yahoo’s erratic actions. We disagree with these latest claims and we will continue to defend ourselves vigorously,” a Facebook spokesman said in an emailed statement.

The patent battle is unfolding against the dramatic backdrop of Facebook’s pending initial public stock offering that is expected to be the largest in Silicon Valley history. Facebook has been adding patents to fortify its portfolio against attacks. It paid Microsoft $550 million for patents from AOL and bought hundreds more from IBM. It has warned investors that an “unfavorable outcome” in the patent dispute with Yahoo could damage its business.

“Yahoo wants to show to Facebook that escalation always goes both ways,” said intellectual property blogger Florian Mueller. “And it tries to make Facebook’s counterclaims look dubious and weak, with a view not only to the court but also the general public and existing or prospective Facebook investors.”

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