The U.S. has revised a copyright law to give legal protection for people who unlock their smartphones, like Apple's iPhone.
The U.S. copyright office passed the amendments to the Digital Millennium Copyright Act, despite strong opposition from Apple. The move is likely to undermine the ability of smartphone producers to control the installation of software on their phones.
Apple says unlocking, known as 'jailbreaking', can violate the product warranty and cause technical problems. Apple sold 8.4 billion iPhones in the last quarter, an increase of 61 percent compared to the same period last year.