Tens of thousands of Internet porn users in the UK have had their emails containing personal information leaked online, along with which content they've downloaded and shared, according to BBC News. The list reportedly includes over 5,300 names and addresses of Sky broadband customers, their IP addresses, and some credit card details.

The entire archive was first uploaded to the Pirate Bay, but has since spread to other file sharing networks, and has been downloaded thousands of times. The list originates from a law firm by the name of ACS:Law Solicitors, which specializes in assisting intellectual property rights holders to exploit and enforce their rights. ACS:Law compiled the list in order to track down Internet pirates and then send letters demanding compensation for copyright holders.

Now, users who have previously received letters from the company demanding money, as well as those who have paid using their credit cards, are being warned to beware of criminals making unsolicited calls and/or unusual transactions. Experts are expecting fraud, identity theft, and severe emotional distress for those affected.

The attack was carried out by 4Chan under the same Payback campaign the site used to target the MPAA and RIAA just over a week ago. ACS:Law's website was taken down by the attack for much of the week, but when it came back up, it appears that the 365MB file containing the confidential information was inadvertently published on the site's front page. While ACS:Law's email archive was exposed after the DDoS attack, there's no evidence that the web server was compromised, meaning that the data breach was caused by poor security and administration.

Protesting against the methods used by ACS:Law to pursue alleged file sharers is one thing, but it gets serious when those the law firm is pursuing have become victims. The UK's Information Commissioner's Office is now investigating the whole ordeal.