Facebook has filed a counter-suit against Yahoo over 10 patents, reports Florian Mueller on Twitter. This is a countersuit to the one that Yahoo filed against Facebook over their own 10 social media patents last month.

Facebook is claiming 10 patents against Yahoo including the following:

Facebook’s General Counsel Ted Ullyot told All Things D that “While we are asserting patent claims of our own, we do so in response to Yahoo’s short-sighted decision to attack one of its partners and prioritize litigation over innovation.”

Earlier this year, Yahoo warned Facebook that it would seek legal action if it did not license between 10 and 20 patents on technologies related to advertising, personalized web pages, social networking and messaging. At that time, Yahoo said “we must insist that Facebook either enter into a licensing agreement or we will be compelled to move forward unilaterally to protect our rights.”

Facebook issued a statement when the Yahoo suit was filed, saying: “We’re disappointed that Yahoo, a longtime business partner of Facebook and a company that has substantially benefited from its association with Facebook, has decided to resort to litigation. Once again, we learned of Yahoo’s decision simultaneously with the media. We will defend ourselves vigorously against these puzzling actions.”

It looks like it has made good on that promis with this suit.

Fb Answer and Counterclaims