Anonymous has posted a video in French, declaring war against Islamic State following a series of terror attacks in Paris that have left at least 129 people dead.

The announcer, hiding behind a Guy Fawkes mask says:

“You should know that we will find you and we will not let you go. We will launch the biggest operation ever against you. Expect massive cyber attacks. War is declared. Get prepared. The French people are stronger than you and will come out of this atrocity even stronger.”

The hacker group has to this date- according to Foreign Policy reports- taken down 149 Islamic State-related websites and exposed 101,000 Twitter accounts and 5900 propaganda videos.

Anonymous which consists of unrelated volunteers, coders and activists from around the world, is known for its cyber attacks against controversial organisations and individuals, and has launched an anti-Islamic State online campaign, called #OpISIS, after the Charlie Hebdo massacre in Paris last January.

The hackers have unmasked the identities of thousands of ISIS-linked Twitter handles over the last nine months.

Source: The Telegraph