Gibson has been involved with Guitar Hero for a long time now in video-game-dog years. It seems there has been a bit of a falling out between Gibson and Activision. It's pretty hard to figure out exactly what happened or is happening. The best I that I can read into the situation from the cheapest of the seats here online is that Activision dumped Gibson, so Gibson decided to do some patent-trolling against a billion dollar video franchise.
Check out Google news for details. A billion real news outlets are covering the story.
I'm still mad at Activision for being dicks about their controllers and Rock Band. The enemy of your enemy is... entertainment. Have fun, Gibson!