According to a new federal policy in the United States that is effective starting Saturday, it will become illegal for certain mobile phone owners to unlock their devices for use on other carriers unless specifically authorized by their carriers. The policy applies to newly purchased devices but not to legacy devices purchased prior to that date. As noted by Tech News Daily:
In October 2012, the Librarian of Congress, who determines exemptions to a strict anti-hacking law called the Digital Millennium Copyright Act (DMCA), decided that unlocking mobile phones would no longer be allowed. But the librarian provided a 90-day window during which people could still buy a phone and unlock it. That window closes on January 26.
In the recently outlined decision in the Federal Register, these policies were cited as reasons for not allowing an unlocking exemption to the DMCA for newly purchased devices:
The Register concluded after a review of the statutory factors that an exemption to the prohibition on circumvention of mobile phone computer programs to permit users to unlock "legacy'' phones is both warranted and unlikely to harm the market for such programs. At the same time, in light of carriers' current unlocking policies and the ready availability of new unlocked phones in the marketplace, the record did not support an exemption for newly purchased phones. Looking to precedents in copyright law, the Register recommended that the class designated by the Librarian include a 90-day transitional period to allow unlocking by those who may acquire phones shortly after the new exemption goes into effect.
Source: Federal Register, Tech News Daily via MacRumors