The speaker in the Anonymous video said:
'We have silenced thousands of Twitter accounts directly linked to ISIS. We severely punish Daesh on the dark net, hacked their electronic portfolio and stolen money from the terrorists.'
'We have laid siege to your propaganda websites, tested them with our cyber attacks, however we will not rest as long as terrorists continue their actions around the world.
'We will strike back against them... we will defend the rights of freedom and tolerance.'
They made a similar threat after the Paris attack but the terror group didn't take them seriously. ISIS's online unit, the Islamic Cyber Army, hit back, branding the group 'idiots' and declaring: 'What they gonna hack…all they can do is hacking twitter accounts, emails, etc.'
ISIS militants use a number of encrypted messaging services, email providers, and GPS blockers to communicate under the radar.
Source: Daily Mail