Wired: Monday, the Copyright Office officially declared that iPhone users are free to "jailbreak" or hack their iPhones and other handsets in order to use any apps they wish. The regulators declared that while a copyright owner might try to restrict the programs that can be run on a particular operating system, copyright law is not the vehicle for imposition of such restrictions. They added that there is no basis for copyright law to assist Apple in protecting its restrictive business model.
Apple notes that jailbreaking may be legal, but it still violates users' warranties.