People who received MP3 players as holiday gifts may want to steer clear of some Web sites that claim to offer legal music but don't have licensing agreements with major music labels, the Center for Democracy and Technology (CDT) said.

CDT, a consumer rights group, has published a list of more than 30 MP3 download sites that don't have licensing deals with major U.S. music labels. The sites, which charge between US$20 and $35 for subscriptions, say they offer music from artists signed to the major labels, CDT said.

Consumers should be aware of the sites on the list, because, in some cases, they may simply provide subscribers popular peer-to-peer (P-to-P) software that's otherwise free, said David Sohn, CDT's senior policy counsel. And customers using P-to-P software to trade unauthorized music files could face lawsuits from the Recording Industry Association of America (RIAA), he said.

"People might get the false impression of what they paid for was legal," Sohn said. "If you pay $25, you might think that $25 goes to compensate the rights holder."

The CDT tried to contact the operators of each site on its MP3 warning list. In each case, the site operators did not respond.

Several of the sites on the list seem to be run by the same people -- they have similar designs and make similar claims. In many cases, the sites are registered outside the U.S., Sohn said.

Some of the sites hedge their claims of being legal in small print. For example, AllCoolMusic.com, which says it offers 12 billion files, includes a disclaimer at the bottom of its front page: "Today, there are 240 million users trading MP3s on legal file-sharing networks. Sharing is not illegal as long as you obey all relevant copyright laws. Sharing copyrighted material, without permission to do so, is illegal. Purchasing a membership in AllCoolMusic.com does not give you license to download or upload copyrighted material. AllCoolMusic.com implores you to respect all copyright laws."

AllCoolMusic didn't respond to CDT's letter, and there's no contact information readily available on the site.

In March 2005, CDT filed a complaint with the U.S. Federal Trade Commission against two Web sites claiming their music and video downloads were 100 percent legal.

The FTC filed a complaint in U.S. court against one of the Web sites, mp3downloadcity.com, obtained an injunction, and eventually reached a settlement with the Web site operator in May 2006. The settlement required the site to refund customers.

The RIAA has focused its lawsuits on P-to-P users that share music with others, not those that simply download music from P-to-P networks. However, if subscribers to these sites would opt to share their music on the P-to-P software some of the sites provide, that could expose them to lawsuits, Sohn said.