The Library of Congress sparked a firestorm late last year when it issued new rules that made it effectively illegal to unlock a cell phone to switch to a new wireless carrier. An online petition on the issue attracted more than 100,000 signatures and prompted a White House statement criticizing the new rule. Members of Congress sprang into action, introducing at least three bills to deal with the issue.

But copyright reform groups panned these bills. Not only did they provide only narrow and temporary relief on the cell phone unlocking issue, the groups said, but they completely ignored the underlying problem: a provision of the Digital Millennium Copyright Act (DMCA) that makes it a crime to "circumvent" copy protection even for lawful purposes.

New legislation sponsored by Zoe Lofgren (D-CA), Thomas Massie (R-KY), Anna Eshoo (D-CA), and Jared Polis (D-CO) takes a broader approach to the issue. In addition to explicitly legalizing cell phone unlocking, the Unlocking Technology Act of 2013 also modifies the DMCA to make clear that unlocking copy-protected content is only illegal if it's done in order to "facilitate the infringement of a copyright." If a circumvention technology is "primarily designed or produced for the purpose of facilitating noninfringing uses," that would not be a violation of copyright.

For example, Lofgren's bill would likely make it legal for consumers to rip DVDs for personal use in much the same way they've long ripped CDs. It would remove legal impediments to making versions of copyrighted works that are accessible to blind users. And it would ensure that car owners have the freedom to service their vehicles without running afoul of copyright law.

"Americans should not be subject to fines and criminal liability for merely unlocking devices and media they legally purchased," said Rep. Lofgren in a press release. "If consumers are not violating copyright or some other law, there's little reason to hold back the benefits of unlocking so people can continue using their devices."

Lofgren's bill attracted enthusiastic support from activists and advocacy groups that had been lukewarm about previous unlocking bills.

"This is the only piece of legislation so far introduced that legalizes both cell phone unlocking, but also the underlying technology for cell phone unlocking," said Derek Khanna, a conservative activist who was fired from his job on Capitol Hill for advocating copyright reform.

"This legislation is exactly what the digital community was asking for," he told us in a phone interview. "It's exactly what the small cell phone providers were looking for. Unlike the other legislation, it actually solves the problem."

Sherwin Siy, an attorney at the advocacy group Public Knowledge, also praised the bill, which he said "addresses a longstanding problem with the Digital Millennium Copyright Act. For too long, the DMCA has been a barrier to consumers, educators, researchers, and others, in ways that don't even protect artists."

"We intuitively understand that if we buy something, we should have the right to modify it, unlock it, or repair it," said Sina Khanifar, the activist who started the White House unlocking petition (and the founder of the activist website FixTheDMCA). "But the DMCA denies us those rights, and it's critical that we push Congress to pass a bill like the one proposed by Rep. Lofgren and her co-sponsors."