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.