WASHINGTON — Internet providers must abide by music-industry requests to track down computer users who illegally download music, a federal judge ruled yesterday in a case that could significantly increase online pirates’ risk of being caught.
The decision by U.S. District Judge John Bates upheld the recording industry’s powers under a 1998 law to compel Verizon Communications to identify an Internet subscriber who was suspected of illegally trading music or movies online. The music industry knew only the person’s numerical Internet address. The ruling means consumers using dozens of popular Internet file-sharing programs can more easily be identified and tracked down by entertainment companies trying to prevent the illegal trading of movies and music. For consumers, even those hiding behind Internet aliases, that could result in warning letters, civil lawsuits or criminal prosecution.

Verizon promised to appeal and said it would not immediately provide its customer’s identity.