Mobile phones purchased beginning Saturday can no longer be legally unlocked by U.S. consumers to enable them to work on different networks.

The reason, as we reported three months ago, was that the U.S. Copyright Office is no longer granting unlocking an exemption to the Digital Millennium Copyright Act. The DMCA makes it illegal to "circumvent a technological measure that effectively controls access" to copyrighted material, in this case software embedded in phones that controls carrier access.

But in all practicality, nothing will really change for consumers. Before unlocking was first exempted in 2006 and again in 2010, the carriers never sued individuals for unlocking their own phones, and they don't plan to. And even when unlocking was exempted and allowed, the carriers and phone makers were successfully suing illicit businesses that bought throw-away phones by the thousands, unlocked them, and shipped them overseas.

Still, the changeover worries Mitch Stoltz, a copyright lawyer with the Electronic Frontier Foundation. That's because now there's nothing preventing the carriers from suing individuals and abandoning the practice of unlocking mobile phones for their customers.

"People will no longer have this solid shield created by the Copyright Office in the event they do get sued over this," Stoltz said in a telephone interview.

The carriers, however, last year told the Copyright Office, which every three years reexamines exemptions to the DMCA, that it did not oppose individuals unlocking their phones. Many carriers provide the service today to individuals, and that won't change.

"The carriers' position has always been, it's never been about individual consumers. Individual consumers have never been the target of any of the lawsuits or enforcement proceedings or investigations," James Baldinger, a lawyer for TracFone and many of the carriers, said in a telephone interview. "They are concerned about traffickers that steal subsidies and in the end increase the cost of wireless for consumers across the United States."

Among the reasons the Copyright Office changed course was because many carriers and phone makers sold unlocked phones and would also unlock them for their customers.

"While it is true that not every wireless device is available unlocked, and wireless carriers' unlocking policies are not free from all restrictions, the record clearly demonstrates that there is a wide range of alternatives from which consumers may choose in order to obtain an unlocked wireless phone," the Copyright Office ruled in October.

The new rule takes effect with new phones purchased beginning Saturday.

There have been hundreds of lawsuits against unlocking enterprises, even when the exemption was granted. That's because exemptions apply only to individual consumers and their own legally acquired devices.

The same applies to jailbreaking. Although the Copyright Office allowed jailbreaking of mobile phones in October, the decision protects individual consumers. Groups that develop and distribute the jailbreaks, however, theoretically could be sued, although the phone developers like Apple and Google have avoided doing so.

In all, according to Baldinger, TracFone has lodged 88 lawsuits against handset traffickers who unlocked TracFones in 12 federal courts across the United States. That litigation has resulted in injunctions and final judgments against 205 companies and individuals, and awards of more than $305 million in judgments, he said.

T-Mobile has filed 38 handset trafficking lawsuits against 103 defendants, and obtained final judgments and permanent injunctions in 34 cases, and have been awarded more than $131 million in damages. Sprint has filed eight cases against 36 handset traffickers and obtained 11 final judgments and permanent injunctions and awarded more than $27 million, he said.

A whitehouse.gov petition to exempt mobile-phone unlocking was started Thursday.