The Library of Congress made several rulings today that reinforce the rights of people who experiment with software and hardware.

The rulings define exceptions the the Digital Millennium Copyright Act, which includes prohibitions against circumventing software designed to lock particular content or software so they can’t be copied or modified by users. These particular exceptions were requested by the Electronic Frontier Foundation, which advocates for digital civil liberties.

Perhaps most significantly, the Library of Congress ruled that users can “jailbreak” their iPhones–allowing the phone to run software that hasn’t been approved by Apple. Another ruling protects consumers’ right to unlock their phones so that they can operate on a network other than that of the carrier who originally sold the device. The third ruling protected the rights of artists who circumvent anti-pirating software in order to extract samples from DVDs for use in remixes. All three of these cases were deemed examples of fair use.

The rulings illustrate just how strange copyright law has become in the digital age. Of all the reasons Apple could give to prohibit jailbreaking iPhones, copyright law is far from the most obvious. Nevertheless, the company argued that jailbreaking iPhones violates its copyright on its operating system, since the modified phones use a modified version of that operating system.

It’s increasingly common for companies and users to battle over how devices, software, and content can be used. That technical battle will continue regardless of the ruling, but it’s good to see that some of the legal prohibitions have been eased.