In a closely watched case governing Internet privacy, a federal appeals court has reinstated a criminal case against an e-mail provider accused of violating wiretap laws. The 1st Circuit Court of Appeals, in a 5-2 vote, ruled on Thursday that an e-mail provider who allegedly read correspondence meant for his customers could be tried on federal criminal charges.

That decision reverses a 2-1 vote by a three-judge panel last year that raised alarms among civil libertarians and even sparked a flurry of efforts in Congress to rewrite wiretapping law in response.

Privacy advocates had warned that if last year's ruling by the 1st Circuit was left untouched, it could usher in more e-mail eavesdropping by the government. In a rare meeting of minds, the U.S. Justice Department also urged that the case not be dismissed. Lawyers for the defense, on the other hand, said that a broad reading of wiretapping law would open the door for prosecutions of Internet service providers performing normal business practices.

The case deals with an indictment of Bradford Councilman, formerly vice president of online bookseller Interloc, which is now part of Alibris.

Interloc provided some of its customers, typically dealers of rare or used books, with e-mail addresses ending in "@interloc.com." Councilman allegedly ordered the creation of a Procmail script, which saved copies of inbound messages from Amazon.com sent to those specialty book dealers, in hopes of gaining commercial intelligence. (Procmail is a popular Unix utility used for sorting and delivering incoming e-mail.)