The Internet hacking group Anonymous said it has identified the social media accounts of Islamic State (IS) sympathisers which has resulted in many of them being shut down.
On Monday, the group announced via a YouTube video that it would launch a cyber-war against IS militants which it described as "vermin" following a series of terrorist attacks on Paris that left over 100 people dead.
Anonymous has also posted the details of at least one physical address of a person it claims is an IS recruiter in Europe.
Ghost Security Group, another online collective, said it had been sending information to the US government about Twitter accounts since January and some of its members were posing as IS sympathisers on the ‘Dark Web’ to gain further information.
"We're playing more of an intelligence role," said the chief executive of the organisation who declined to be named.
The group is a volunteer organization that has been sending data to the FBI and other agencies via a US counter terrorism adviser, Michael S. Smith II.
Smith said the group's infiltration efforts had given some useful information to the government and has helped push IS supporters away from Twitter towards the Telegram messaging platform.
U.S. agencies "appreciate the outside support. I have constant feedback to that," he said.
"More accounts are being taken down," said J.M. Berger, a Brookings Institution expert on IS. "I do think the majority of the reporting is being done by groups like Anonymous and Ghost Security. But there are other initiatives, including the Counter Extremism Project and the Sawab Center, which are contributing to reporting efforts."
Following Monday’s announcement by Anonymous, a message released on Telegram through an IS affiliated official channel, called members of the group ‘Idiots’ and offered a series of tips to its supporters on how to prevent getting hacked.
The Ghost Security Group leader said his organisation was gathering information about users on Telegram and had launched denial-of-service attacks on websites associated with IS.