Richard O’Dwyer would also face pre-trial imprisonment in a US federal detention centre as a foreign national with no ties to the country, Ben Cooper told Westminster Magistrates’ Court in London.
“Mr O’Dwyer is a young man yet to complete his degree and his social environment would be removed from him,” he said.
“That is going to impact on his reaction to finding himself surrounded by the sort of people who will inhabit a federal detention centre in New York.
“He would be a fish out of water in such an environment. One cannot underestimate the risks that would pose to him.”
O’Dwyer, aged 23, a Sheffield Hallam University undergraduate, is fighting extradition to New York where he is wanted to stand trial on charges of copyright infringement and conspiracy to infringe a copyright over his website, TVShack.
The US government claims the site offered free downloading and streaming of thousands of copyrighted films and TV programmes without permission.
O’Dwyer earned money through hosting adverts on the site, allegedly receiving more than $230,000 in advertising revenue since January 2008, according to the US authorities.
Cooper argued that the site did not store any copyrighted material but merely pointed users to other sites where they could download films and TV shows.
His website linked to other websites in the same way Google and Yahoo! operate, he argued, and people were not able to view a film from TVShack directly.
Cooper added that his client would be the first British citizen to be extradited for such an offence and would effectively become a “guinea pig” for copyright law in the US.
But John Jones, for the US authorities, told the court the victims of the alleged offences included the film studios. He said that the website highlighted the savings that could be made in cinema tickets in the US.
Judgment on whether to extradite O’Dwyer was reserved until January.