A US student could face $4.5m (£2.8m) in fines following a federal court ruling that he violated copyright law for sharing music files online.
The jury must now decide on the amount of damages it will award to the four recording labels that are suing him.
Joel Tenenbaum admitted on the witness stand on Thursday that he had used file-sharing sites both to download and upload hundreds of songs.
It is only the second music-downloading suit to go to trial in the US.
Last month saw the end of the first such suit, in which single mother Jammie Thomas-Rassett of Minnesota was ordered to pay $1.92m for sharing 24 songs.
Mr Tenenbaum used a computer at his parents’ home and at his college to download and distribute digital files.
Prosecutors working on behalf of the record labels have focused on 30 shared songs.
Under US law, the recording companies are entitled to $750 to $30,000 (£450-18,000) per infringement.
However, the jury can raise the amount to $150,000 (£91,000) per track if it finds the infringements were wilful – a matter that they will debate now that the judge has ruled Mr Tenenbaum violated copyright laws.
“ It was like this giant library in front of you ”
In the Minnesota case, the jury awarded $80,000 per song.
On the stand, Mr Tenenbaum admitted that he had downloaded more than 800 songs since 1999 and that he had lied in pre-trial proceedings when he suggested that other family members of friends may have been responsible for downloading songs to his computer.
"I used the computer. I uploaded, I downloaded music," he told the court under questioning from his own lawyer, Charles Nesson.
He said he had used Napster and then Kazaa to download the files.
"It was like this giant library in front of you," he said.
In opening remarks on Tuesday Tenenbaum’s lawyer said he "was a kid who did what kids do and loved technology and loved music".
Recording companies had been slow to adapt to the internet, he added.
But prosecutors argued that file-sharers take a significant toll on the revenues for artists and others involved in music
The recording industry has recently changed its tactics in file sharing cases, preferring to settle quickly for much smaller amounts.
However, cases such as those against Mr Tenenbaum, which were already filed, are proceeding to trial.
The four recording labels involved in the case are subsidiaries of Universal Music, Warner Music and Sony.
Source: BBC News