A jury in Boston has decided that grad student Joel Tenenbaum should pay the record labels $675,000 for using peer-to-peer software to share 30 tracks.

The decision, issued late Friday, marks the second major courtroom victory for the Recording Industry Association of America against an individual file-sharer. In June, a jury in Duluth, Minn. ordered Jammie Thomas-Rasset to pay $1.92 million for sharing 24 tracks.

When Tenenbaum was on the witness stand, he admitted that he used Kazaa, Limewire and other services to share songs by groups like Green Day and Nirvana. After he testified, U.S. District Court Judge Nancy Gertner ruled that Tenenbaum had infringed on the labels' copyright, but that the jury should decide whether the infringement was "willful." Gertner also left it to the jury to decide how much Tenenbaum should pay in damages. The statute provides for a minimum of $750 per track and a maximum of $150,000 per track.

In testimony that proved fatal to his case, Tenenbaum answered "yes" when asked whether he was admitting liability. Gertner relied on that statement when she decided that Tenenbaum infringed copyright, taking that question out of the jury's hands.

But it's not clear that Tenenbaum's testimony about liability should have settled the issue. Attorney Ray Beckerman, who has represented other defendants in file-sharing cases, wrote on his blog, Recording Industry vs. The People, that Gertner's decision on that point was wrong. "The question: 'Are you admitting liability?' is a legal question, not a factual question, which Mr. Tenenbaum was not qualified to answer," he wrote.

Since 2003, the RIAA has filed around 30,000 lawsuits against individual file-sharers. Tenenbaum and Thomas-Rasset are the only two individuals who have asked for jury trials. Many of the others settled for between $3,000 and $5,000.

Tenenbaum and Thomas-Rasset both argued that damages of up to $150,000 per infringement are unconstitutional because they appear to be higher than the actual harm to the industry caused by any one file-sharer. Gertner delayed ruling on that issue before trial, but said she would revisit it later if the jury came back with a damages award.

Last December, the RIAA said it planned to stop bringing new lawsuits against individual file-sharers.