In a break with other Internet service providers, AT&T will work with Hollywood studios and recording labels to devise technology that <A HREF="http://www.cnn.com/2007/TECH/06/15/att.online.piracy.ap/index.html">identifies offshore content pirates</A> who use its network to upload illegal copies of movies and music.

Although details remain sketchy, the effort worries privacy advocates, who fear the San Antonio-based company could become a beat cop, monitoring which Web sites customers visit and what computer files they share.