Internet search and services firm Yahoo is suing social networking king Facebook, accusing it of ten patent breaches.
"Yahoo's patents relate to cutting edge innovations in online products, including in messaging, news feed generation, social commenting, advertising display, preventing click fraud and privacy controls," the lawsuit claims.
"Facebook's entire social network model, which allows users to create profiles and connect with, among other things, persons and businesses, is based on Yahoo's patented social networking technology.”
Facebook itself has publically lamented Yahoo's approach, saying that it is surprised the firm has chosen to go legal after just a couple of phone calls”.
A statement added: "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.”
The news comes following a turbulent period at Yahoo.
The company sacked its CEO Carol Bartz in September, replacing her with former PayPal executive Scott Thompson. Co-founder Jerry Yang resigned from the firm in January.
Although patent litigation is common in the smartphone and personal computing market, this is the first major case in the social media sector – and one that could give Yahoo a significant financial boost.