The lawsuit, which was filed in federal court in San Jose, Calif., details patents related to messaging, social networking, privacy, customization and advertising.
"Yahoo! has invested substantial resources in research and development through the years, which has resulted in numerous patented inventions of technology that other companies have licensed," explained a spokesman for the Internet firm. "Unfortunately, the matter with Facebook remains unresolved and we are compelled to seek redress in federal court -- we are confident that we will prevail."Facebook expressed surprise at Yahoo!'s legal action in an email to TheStreet. "We're disappointed that Yahoo's effort to engage with us was limited to a few short phone calls and that we continue to learn of new developments about a long-time partner through the press," explained a spokesman. "We will defend ourselves vigorously against these puzzling actions." Shares of Yahoo!, which recently appointed PayPal president Scott Thompson as its CEO, were flat at $14.49 in extended trading on Monday. Facebook recently filed to go public, seeking to raise $5 billion in what would be the largest-ever tech IPO. -- Written by James Rogers in New York >To follow the writer on Twitter, go to http://twitter.com/jamesjrogers. >To submit a news tip, send an email to: email@example.com. Check out our new tech blog, Tech Trends. Follow TheStreet Tech on your wireless devices.