Nintendo sued for patent infringement

In the same way that Sony and Microsoft were sued for using rumble in their controllers, now Nintendo is being sued by another company:

Interlink Electronics is suing Nintendo over the Wii Remoteâ??s trigger button, which Interlink claims to be its own original patented design (patent no. 6,850,221).

Yes, you read it correctly, they’re suing Nintendo over a button. Not the Wiimote’s shape, not it’s movement and tilting sensor, but just it’s “B” trigger button. Why didn’t they sue Nintendo back when they made the Nintendo 64 controller?