More than 160,000 people have signed a petition launched by the founder of internet encyclopaedia Wikipedia to block the extradition of a British student to the US on copyright charges.
Jimmy Wales, 45, came out in support of Richard O'Dwyer, 24, who faces up to 10 years in prison if convicted of charges relating to his website, TVShack.net.
Some 164,000 people have signed the online petition in just five days.
O'Dwyer's supporters argue that as the site, which linked to other sites that streamed pirated television programmes, did not host material itself he should not face any charges and should therefore not be extradited.
Mr Wales called on Home Secretary Theresa May to stop the extradition, calling the interactive media and animation student "the human face of the battle between the content industry and the interests of the general public".
O'Dwyer's mother Julia said: "I'm blown away by the response to Jimmy's petition.
"It's been a tough year campaigning for my son but this outpouring of support from around the world has really made politicians sit up and take note of Richard's case.
"Now it's time for Theresa May to do the right thing by Richard."
Earlier this year, Wikipedia blacked out the English language version of its website in protest at anti-piracy laws being considered by the US government.
Rachel Robinson, of the human rights group Liberty, said: "The overwhelming support for Richard should send a message to the Government about the public's outrage at our rotten extradition regime - which both coalition partners opposed in opposition.
"It's a mystery why people in Britain are still being hauled from their bedrooms off to foreign courts without any semblance of justice or common sense."
Jago Russell, chief executive of Fair Trials International, added that the time for talk was past.
"This massive public response to Richard O'Dwyer's case must surely make Government realise it now has to get on with the job of fixing our broken extradition laws," he said.
"Until our laws are reformed countless more people will suffer the devastating impact of unjust extradition."