An ISIS guide to operational security has been published by Wired. The ISIS guide includes most of the recommendations provided by civil liberties, privacy defender, and journalist groups when dealing with surveillance operated by many regimes across the world. It bans the use of Instagram, Apples iMessage and WhatsApp, despite both implements end-to-end encryption the jihadists believe that companies spies on behalf of the US Government. It also warns that mobile communications can be intercepted and recommends followers to use crypto phones like Cryptophone or BlackPhone instead.”]
Source: http://securityaffairs.co/wordpress/42115/hacking/opsec-isis-guide.html