He's at an Alaska Wildlife Conservatory. The article says he's 5 years old and was someone's pet for a while.
http://www.huffingtonpost.com/2010/0..._n_651453.html
Interesting note about porcupines (fact learned from a recent zoo visit with my daughter's brownie troop): They don't actually throw or shoot quills. They bristle them up and let their predators run in to them.