People claiming to be part of the hacking protest group Anonymous have apparently published contact details of English Defence League members online.
The names and addresses of more than 200 people from across the country are said to be on the list, the BBC reports.
The mobile numbers of senior EDL members are also thought to have been included on the list.
More top news
Figures from the latest ComRes poll shows 58 percent believe David Cameron will not get a good deal for Britain.
Lottie and her dog Marley confronted a man who had taken a laptop and goods from a Lush store in Oxford.
Feeling colder with a biting, bitter windchill