About four years ago ( http://www.engadget.com/2006/08/04/microsoft-and-nintendo-keep-up-with-sony-get-sued-for-controlle/ ) — a little Texas company called Anascape sued Nintendo and Microsoft for ostensibly violating its controller patents. Microsoft settled. Nintendo didn't. Anascape won. One $21 million judgment, two years and countless legal bills later, Nintendo has finally emerged victorious over the patent troll.
This week, a Federal Circuit Court overturned two earlier decisions, ruling that Nintendo's GameCube, WaveBird and Wii Classic Controllers don't violate Anascape's six-degrees-of-freedom patent, because Anascape only added that 6DOF claim to its patent in 2000... making Sony's original DualShock controller — released in 1998 — prior art. Game, set, match.
Engadget : http://www.engadget.com/2010/04/14/nintendo-escapes-patent-troll-in-appeals-court-thanks-to-sony/