Hackers claiming to be from the protest group Anonymous publish the addresses and contact details of 200 people they say are members of the English Defence League.
The leak of information came after the group posted a video on Youtube vowing to bring down the EDL.
The group, thought to be linked to hacktivists Anonymous, condemned the EDL for using the death of Drummer Lee Rigby as an “another excuse to further spread your campaign of hate, bigotry, and misinformation” before it announced “Operation EDL” and published the data.
Under the guise of national pride you have instigated crimes against the innocent and incited the subjugation of Muslims – Online video
A list of what the hackers said were mobile phone numbers for senior named EDL figures were published online yesterday evening, along with addresses of what were said to be donors to the group.
The video was posted by IWill Object under the title “a message from Anonymous UK to the English Defence League”.
“Under the guise of national pride you have instigated crimes against the innocent and incited the subjugation of Muslims,” the message continued.
Read more: who are the EDL?
“We will not allow your injustices, your lies, and your stupidity, to further radicalise our youth into fearing and despising their fellow man.”
The warning concluded: “In this operation, we will begin the systematic and comprehensive decimation of your cult.
“We will further expose your falsities and your attempts to censor, to your members, to the British public, and to the world as a whole. You will fall, we can say this with complete confidence.”
There have been a number of EDL street demonstrations following the murder of Drummer Lee Rigby in Woolwich, including a gathering of hundreds at Downing Street on Monday.
EDL supporters chanted “Muslim killers off our streets” and “There’s only one Lee Rigby” in tribute to the soldier killed in Woolwich last week.
Four men have since been charged with various offences. A massive police presence kept them apart from a smaller group of anti-fascist activists, with officers making 13 arrests in total.
EDL leader “Tommy Robinson” (as he is known publicly) had also planned to do a sponsored walk to raise donations for Help for Heroes. However the forces charity said it would not accept the money.