Almost 25,000 Americans are being pursued through the courts by the producers of The Hurt Locker for alleged piracy, it has emerged.

A lawsuit filed by Voltage Pictures, the production house behind the Oscar-winning Iraq war drama, has broken the record for the largest ever online copyright infringement claim, previous held by The Expendables.

The firm accuses 24,583 unnamed, or “John Doe”, defendants of unlawful sharing The Hurt Locker via BitTorrent, the peer-to-peer filesharing network.

Court papers published by the Torrentfreak blog reveal Voltage Pictures is pushing broadband providers to identify its targets by matching a list IP addresses to their actual customer records. The largest proportion, 10,532, are subscribers to the cable giant Comcast.

The production house and its lawyers, US Copyright Group, were able to gather the list of thousands of IP addresses because to join a BitTorrent “swarm” - a group sharing a particular file - filesharers must effectively broadcast an IP address.

There are ways savvy users can conceal their own IP address however, such as by using someone else's unsecured WiFi network, so the strength of the evidence used by US Copyright Group is often disputed.

The BitTorrent protocol breaks large files up into small chunks which are directly shared between users. It differs from from earlier filesharing systems such as Napster in that there is no central company or server that could be shut down by through the courts by copyright holders.

It is unclear what action Voltage Pictures will take against those individuals it identifies, but in previous cases US Copyright Group has written to alleged pirates asking for around $3,000 to avoid a court case that could cost many times more.

Similar tactics, sometimes branded "speculative invoicing", were controversially used in the UK by ACS:Law, a London-based sfirm of solicitors that accused thousands of people of unlawfully sharing videogames and films, including pornography.

The firm was recently wound up but its founder, Andrew Crossley, faces a Solicitors Regulation Authority hearing over his conduct next month.

Telegraph.co.uk