Facebook will be held accountable for patent infringement.

Walker Digital has accused Facebook of illegally using its patented technology.

Walker Digital operates the airline and hotel booking service Priceline.com. According to Walker Digital, Facebook is illegally using its technology for anonymous communication between internet users and its online personal data management systems.

Walker Digital's claims may be related to Facebook's launch of its email service, which was announced several days ago. Facebook considers the lawsuit unfounded.