SYDNEY (AP) — Internet providers lost an Australian court battle on Tuesday to keep secret the names of Internet users suspected of illegally downloading Hollywood movie “Dallas Buyers Club” over file-sharing networks.

The Federal Court ruling is a landmark win for copyright holders in a country which has a reputation for being among of world’s most prolific Internet pirates.

Justice Nye Perram granted a discovery order sought by the 2013 movie’s copyright owner Dallas Buyers Club LLC to access names and home addresses of more than 4,700 Australian Internet account holders.

But he said the privacy of the Internet users should also be protected by court orders that have yet to be decided. These orders would prevent the movie owners from making the personal details public.

Any letter that the movie’s owner intended to send to those users demanding compensation for movie piracy would also need to be signed off by the judge.

Dallas Buyers Club LLC and its parent company Voltage Pictures LLC targeted six Australian Internet service providers — iiNet, Internode, Dodo, Amnet Broadband, Adam Internet and Wideband Networks — when they sought personal details associated with more than 4,700 Internet Protocol, or IP, addresses that were allegedly used to share “Dallas Buyers Club” using BitTorrent.

The ISPs opposed the application at a hearing in February, citing concerns that the filmmakers could intimidate subscribers with so-called “speculative invoicing” — a strategy that involves sending intimidating letters threatening legal action and seeking large sums of money for breach of copyright.

“I will order the ISPs to divulge the names and physical addresses of the customers associated in their records with each of the 4,726 IP addresses,” Perram said.

This information can be used only for recovering compensation, he said.

“I will also impose a condition on the applicants that they are to submit to me a draft of any letter they propose to send to account holders associated with the IP addresses which have been identified,” Perram said.

Detailed orders will be thrashed out when the case returns to court on April 21.

It is not clear whether the ISPs will appeal the decision before the Full Bench of the Federal Court.

Copyright holders’ lawyer Michael Bradley told reporters the case would set a precedent.

“The next step is identifying the users, and then what we do after that hasn’t been decided,” he said.

“I don’t know what impact it will have on piracy. Certainly, Australia is one of the jurisdictions with the highest rate of unauthorized downloading and this is a first step from a copyright owner to try to change that balance,” he added.

The 2013 drama about AIDS in 1980s Texas earned Oscars for Matthew McConaughey as best actor and Jared Leto as best supporting actor and was nominated for best picture.

Hundreds of copyright infringement lawsuits have been filed over the film in the United States as well.