Anonymous are not the only group fighting terrorism in the shadows of the internet.
While the global hacking collective in the Guy Fawkes masks have waged a high profile cyber war on ISIS - taking down thousands of Twitter accounts and exposing alleged IS members, another clandestine organisation has joined the fight.
But the Ghost Security Group is silently spying on ISIS activity online rather than trying to wipe them off the net.
The group claims to have thwarted an Islamic State terror plot in Tunisia just 30 days after the massacre at Sousse beach which left 39 dead.
GSG monitors jihadist communications on online chat rooms and forums and then gives tip-offs to international security services.
https://twitter.com/GhostSecGroup/status/668257909399232512
They claim that this spy tactic prevented another atrocity on the Tunisian island of Djerba which is popular with British holidaymakers.
Michael Smith, chief operating officer of security consultancy Kronos Advisory which acts as a link between GSG and the security services, claimed the attack could have left scores of people dead.
Speaking to the BBC, he said: "They are not just identifying channels of communication, they have put together a list of accounts which are utilised by people with influence.
"A tweeting jihadi is a targetable jihadi. These people have saved lives."
Ghost Security Group have criticised Anonymous' approach to tackling ISIS online.
The group's security director, speaking anonymously to the BBC, said: "They [Anonymous] don't have any counterterrorism experience whatsoever.
"We felt that not enough was being done and the Charlie Hebdo attack made it clear that ISIS was not confined to the Middle East.
"We would much prefer to stop attacks than shut down websites. I don't think DDoS attacks do a huge amount of damage to Islamic State.
"Anonymous are hitting some extremist forums that have intelligence value, but we would like forums to stay online so we can see what people are saying and gather intelligence from them."
Anonymous say taking down Twitter accounts stops the spread of propaganda and young people being influenced by their terrorist ideologies.
