A LANDMARK court ruling handed down yesterday will have lasting implications for the ongoing fight against illegal downloading and file sharing.

The Federal Court Justice, Nye Perram handed down the verdict in favour of Dallas Buyers Club LLC at 2.15pm yesterday.

The Hollywood studio had requested that iiNet (and a few other Australian ISPs) divulge the identity of customers whose IP addresses were found to have shared the film Dallas Buyers Club illegally.

The company owns the rights to the movie and identified a total of 4726 IP addresses that engaged in the illegal activity. The ruling means that the company will now be given the contact details of the offenders and will be able to pursue them directly for compensation.

Justice Perram says "preliminary discovery" of iiNet customer details should be granted in case against Dallas Buyers Club #iiDallas — Claire Reilly (@reillystyley) April 7, 2015

Australian Federal Court has ruled iiNet must hand over the names & addresses of 4726 customers who illegally downloaded Dallas Buyers Club. — Alice Workman (@workmanalice) April 7, 2015

While iiNet challenged the request, the successful suit could result in thousands of Australians being sued directly for copyright breaches.

Other ISPs that will have to hand over their customers data include Internode, Adam internet, Amnet Broadband, Wideband and ISPs Dodo.

The information to be disclosed by ISPs include the names, email and residential addresses of those who allegedly committed the copyright breach.

The IP addresses identified belonged to those who “seeded” the movie, making it available for download by others on a peer to peer network. It is understood the rights holders employed technology from German firm Maverickeye UG, which according to the company’s website helps rights holders detect and retrace copyright infringement.

Prior to the decision, the Hollywood studio stated they will send letters to the offenders seeking compensation.

However during the case, iiNet raised concerns over “speculative invoicing” in which rights holders send aggressive letters to those in breach of copyright, threatening legal action and asking for a disproportionate amount of compensation to avoid a court case. The tactic was used by the company in similar cases in the US.

While Justice Perram could have placed a cap on the dollar amount that could be sought through such extrajudicial methods, he chose not to. He did, however, order that any letters being sent to the alleged offenders must be seen by him first.

There is no indication yet as to whether iiNet will appeal the decision, but they have 28 days to do so.

The watershed verdict in favour of the rights holder will no doubt have a major impact on Australian ISPs and their customers. Many of whom can now anticipate a rude letter in the mail.