Yahoo is suing Facebook, accusing the social media giant of building its empire on technology covered by Yahoo's social media patents.
Yahoo has filed a patent infringement lawsuit covering ten patents, and is seeking triple damages and an injunction on Facebook operating the allegedly infringing services.
In the suit, Yahoo claims that Facebook's entire social network model is based on social networking technology patented by Yahoo. A successful injunction, however unlikely, could thus require Facebook to effectively shut up shop.
The suit also comes at a time Facebook is preparing for an IPO worth as much as $100 billion, and could potentially be a spanner in the works for this process.
All Things Digitalreports that the move, believed to be spearheaded by new CEO Scott Thompson, is a contentious one within the company.
A number of Yahoo employees are opposed on the grounds that it violates the company's usual strategy of using patents only defensively.
Yahoo first threatened to sue Facebook in late February, unless Facebook agreed to license Yahoo's social networking patents.
In a press statement, Facebook expressed disappointment that its long-time partner has “decided to resort to litigation,” complaining that it was told about the possibility of the lawsuit only at the same time as the media.