Read my posting on the "stupidity of the secret question".
Then read this article: MacDevCenter.com: How Paris Got Hacked?
Paris Hilton's phone may have been hacked because she used her dog's name as a sort of global password. Unfortunate but, frankly, completely commonplace. It is, however, inexcusable that T-Mobile uses those idiotic "secret questions", such as "name of your dog" to do password resets.
Paris has enough money to sue T-Mobile from here to Mars. I sincerely hope she makes them suffer.