File-sharers can find out if they are being targeted by the US record industry via a website created by civil liberty activists.
The Electronic Frontier Foundation, (EFF), has set up an online database which allows people to check if a subpoena has been issued for them by the Recording Industry Association of America, (RIAA).
"We hope that EFF's subpoena database will give people some peace of mind and the information they need to challenge these subpoenas and protect their privacy," said the group's senior lawyer Fred Von Lohmann.
Hundreds of subpoenas have been sent to suspected file-sharers as part of the industry's battle to stop people swapping songs over the internet.
Using the EFF site, people can check the name they used for file-sharing against a list of subpoenas issued in a Washington court.
If someone finds their name in the database, they can look at an electronic copy of the subpoena.
This includes the name of the internet service provider, a list of songs pirated and the internet address of the user.
The EFF site takes its information from a US justice system called Pacer. Its online database lets people to gain a wide range of information about ongoing cases.
By the end of last week almost 900 subpoenas had been issued, with the courts granting more than 75 every day.
Advice to file-swappers
The subpoenas are part of the industry's battle to clamp down on music piracy, spearheaded by the RIAA.
They will force telecommunications companies to identify file-swappers, who are usually only known by their online user names.
People charged with piracy could face lawsuits for damages ranging from $750 (£480) to $150,000 (£96,100), which are applicable under US copyright laws.
"The recording industry continues its futile crusade to sue thousands of the more than 60 million people who use file-sharing software in the US," said Mr Von Lohmann.
The EFF is also offering advice to file-sharers who are facing legal action.
Together with the US Internet Industry Association, it has set up a website called subpoenadefense.org which has details of lawyers and other legal resources.
The civil liberties group is also providing tips on how to avoid being sued by the record industry.
These include removing all copyrighted material from a computer and disabling the file-sharing facility on programs such as Kazaa and Grokster.