For the first time ever, Apple has said publicly that jailbreaking iPhones is illegal. In comments filed with the US copyright office, Apple says that jailbreaking is copyright infringement and a violation of the DMCA.
Every three years, the US Copyright Office has a rulemaking session for the Digital Millennium Copyright Act, where exemption requests can be filed. For the 2009 session, the Electronic Frontier Foundation filed an exemption request for jailbreaking iPhones for the purposes of interoperability with independent software—i.e., apps not in the App Store.
Apple filed these comments (warning, PDF) in opposition, which is the first time it's explicitly said that jailbreaking itself is illegal ('cause copyright infringement is, well, not legal). It gets pretty nasty trashtalking the EFF in parts, and pretty masturbatory talking about how amazing the iPhone is in others (to show how it doesn't need to be opened to foster innovation). But the bottom line, according to Apple, is that the act of jailbreaking itself constitutes copyright infringement because it "involves infringing uses of the bootloader and OS, the copyrighted works that are protected by the TPMs being circumvented."
The EFF's counter-argument is that "courts have long recognised that copying software while reverse engineering is a fair use when done for purposes of fostering interoperability with independently created software." Apple says, whatever, it's not fair use, you suck.
We'll let the lawyers figure it out, but as a betting man, my money's on the Fruit. [EFF]