An Australian federal court has ordered Internet Service Providers to hand over the names and addressed of over 4,000 people who have engaged in illegal movie downloading.

The case, if it is not overturned on appeal, could be a landmark and see rights holders able to act against anonymous file shares. In a number of other previous cases, Australian courts sided with the ISPs against the rights holders who had sought trial.

The new case, concerning “Dallas Buyers Club,” which was shared on BitTorrent, was heard by the court in February.

The judgement said that the ISPs could only use the data to obtain compensation for the infringements. And the court even required the plaintiff, Dallas Buyers Club LLC, to submit a draft of the letter to be sent to the downloaders.

There was argument about the small size of the claims against each infringer and whether the rights holders might bully the infringers into paying in order to avoid large legal coasts.

But the judge said that damages could in the future be awarded that are sufficiently large to have a deterrent effect.