Hacking group Anonymous declares WAR on ISIS after horrific Paris terror attacks
In a YouTube video the bold hackers said they will launch their "biggest operation ever" and warned the sick terrorists to "expect us".
Behind their signature mask, a spokesman warned: "Anonymous from all over the world will hunt you down.
"You should know that we will find you and we will not let you go.
"We will launch the biggest operation ever against you."
The masked man also warned the brutal terror group to "expect massive cyber attacks".
He said: "War is declared. Get prepared.
"The French people are stronger than you and will come out of this atrocity even stronger."
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After the Charlie Hebdo attacks in January, the hackers started publishing a list of Twitter accounts allegedly spreading propaganda for the terrorists.
Over the weekend ISIS claimed responsibility for the latest savage terror attacks in Paris.
The brutes targeted six locations across the French capital, including Stade de France where president Francois Hollande was watching a national football match.
Jihadis also attacked cafes and restaurants where people were enjoying a Friday night out.