An online petition to legalize the practice of unlocking cell phones crossed Thursday the 100,000 signature threshold that qualifies for an official response from the White House.

Unlocking a cell phone frees it up to be used on carriers other than the one on which it was originally intended to operate. Historically, it's been a popular practice among world travelers who use unlocked devices to access foreign carriers' networks and among those who enjoy the freedom to change carriers without incurring costly early termination fees (however, the latter group can still be inhibited by phones' inability to work on other carriers' different wireless technologies).

Unlocking cell phones became illegal last month after the Librarian of Congress, who decides upon exemptions from the Digital Millenium Copyright Act every three years, determined the practice would no longer be excluded from DMCA restrictions. The rule change came with one caveat: wireless customers can still ask their carriers to unlock their phones. Some carriers provide phones that come unlocked out of the box, such as Verizon's iPhone 5.

Even still, many communications activists, including the creator of the White House petition, argue last month's change to the DMCA exemptions reduces customer choice and subjects customers to the whims of service providers.

The petition was written by entrepreneur Sina Khanifar, who in 2005 faced prosecution under the DMCA for selling phone unlocking software, though Motorola dropped its case against him.

"Consumers will be forced to pay exorbitant roaming fees to make calls while traveling abroad," reads Khanifar's petition. "It reduces consumer choice, and decreases the resale value of devices that consumers have paid for in full."

"Thanks for tweeting, very glad to have made it to 100k signatures," Khanifar told Mashable via e-mail. "Obviously I'm aware that the [White House] may fail to make a meaningful response (though I'm hopeful!) but I'm urging everyone who's interested in this to sign up at http://fixthedmca.org for news on future activism on this issue."

SEE ALSO: Unlocking Cellphones Becomes Illegal Saturday in the U.S.

The Electronic Frontier Foundation, a leading communications activist group, believes that carriers aren't likely to sue individual customers who choose to unlock their phone, but instead target mass resellers of unlocked devices. The EFF admitted, however, that there's not much that can be done outside of potential judicial or legislative action until debate over the next round of DMCA exemptions begins late next year.

"Creating and defending the next round of exemptions will start in late 2014," wrote the EFF's Mitch Stoltz in a blog post. "If lawsuits happen, the courts should recognize that the DMCA is being misused, and refuse to apply it to anti-competitive software locks. Ultimately, what we really need is to either fix the exemption process or reboot the anti-circumvention provisions of the DMCA, or both."

The White House recently raised the signature threshold which requires an official response to 100,000 signatures from 25,000. Mashable has contacted the White House and will update this post with any response.

What should the White House do about unlocking phones and the DMCA? Share your thoughts in the comments.

Photo via iStockphoto, kizilkayaphotos