Ten Internet Service Providers have been ordered to hand over the details of 150 UK customers accused of illegally sharing software.
The High Court order follows a 12-month covert investigation by the Federation Against Software Theft (Fast).
Among the Internet providers are BT, NTL, Telewest and Tiscali.
Over the next two weeks, they are expected to provide the names, addresses and other personal details of the alleged file-sharers.
An undercover investigator working for Fast in a project codenamed Operation Tracker identified 150 people suspected of illegally sharing software.
Most file-sharers use false names and email addresses. So the software anti-piracy group went to the High Court to force the internet providers to hand over customer details.
The federation said it would approach the police and Crown Prosecution Service once it has the personal information.
"We can easily take down links, but this does not tackle the root causes of software piracy, because the links will reappear elsewhere in a matter of hours," said John Lovelock, director general at Fast.
"Instead, we plan to take action a lot further, making an example of the perpetrators to stop them from stealing and passing on the intellectual property of our members for good."
The federation accuses the 150 individuals of breaking copyright law by uploading software and sharing it online.
Penalties for the illegal communication to the public of copyrighted works, including software, can attract a maximum punishment of up to two years imprisonment and/or an unlimited fine.
Julian Heathcote Hobbins, Fast's senior legal counsel, said the court action was "only the first wave of an ongoing strategy".
"We expect to be bringing these actions anytime and anywhere we see software being misused," he said.
According to the anti-piracy trade group, the Business Software Alliance, about a quarter of software used in the UK is an unlicensed, counterfeit or pirated copy.
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