Microsoft is suing U.K.-based third-party memory card and controller maker Datel in the United States federal court for allegedly infringing multiple Microsoft patents. It is unclear which specific patents Microsoft claims have been infringed, though Microsoft is alleging that Datel's Xbox 360 controllers - in particular "TurboFire" and "WildFire" - appear to be based on Microsoft's official Xbox 360 game pads.
Microsoft is seeking unspecified damages for this alleged infringement, as well as an injunction on the manufacturing of the controllers, and a payment of the profit or royalties that Datel has received to date for its sales of the controllers. The controllers run for about $35USD in the United States.
This is just the latest round in what seems to be an ongoing battle between Datel and Microsoft - see here and here for details on Datel's anti-trust suit against Microsoft.