Verizon met the Recording Industry Association of America in an appeals court yesterday to continue their battle over an earlier ruling that an ISP should be forced to reveal the identity of a customer accused of internet piracy for using file-sharing, or P2P services.

The case dates back to August last year when the RIAA took the telecoms giant to court because it refused to identify customers who were making available MP3 files of copyrighted songs from their home computers, using file-sharing services like KaZaA. Until this time, the RIAA had concentrated its legal efforts on those providing the P2P services.

The RIAA had served a subpoena on Verizon – basically a demand for the identity of alleged infringers – under a provision of America's controversial Digital Millennium Copyright Act (DMCA).

This provision states:

"a copyright owner or a person authorized to act on the owner's behalf may request the clerk of any United States district court to issue a subpoena to a service provider for identification of an alleged infringer".

A judge is not involved in the issue of the subpoena.

Verizon argued that because the allegedly infringing files resided on a home PC, not Verizon's servers, the subpoena was not valid. The RIAA countered that the legislation does not specify that the infringing material reside on the ISP's network.

In January, the court decided in favour of the RIAA and Verizon immediately asked for a stay in identifying its subscribers while the decision was appealed. The court provided only a temporary stay, which was lifted in June.

Consequently, the two subscribers were identified and they promptly settled with the RIAA. More significantly, the decision opened the door for the RIAA to issue more subpoenas.

Since June, the RIAA has issued more than 1,600 of them, followed by 261 lawsuits so far against identified file-sharers. Many more actions are expected to follow.

Verizon has only just begun its appeal against the decision on the use of DMCA subpoenas. A three-judge panel of the federal appeals court yesterday heard arguments, focusing mainly on technical issues surrounding the interpretation of the DMCA, rather than Verizon's broad allegations that the subpoenas breach privacy and free speech rights.

The appeal will decide whether the RIAA can continue to use ISPs to identify file-sharers or whether it will have to adopt another tactic.

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