Yes, ISIS Is Using Encryption — But Not Very Well
This article discusses other older news articles pre-dating the 9/11 terrorist attack in NY, NY. It demonstrates that terrorists were using encryption at least 6 month prior to the attack and certainly it can easily be extrapolated that in order to use you had to know about encryption before you began using it. This article also explains that encryption technologies are prolific. The program Telegram is produced by a German entity and WhatsApp is based on open source technology, where in neither case will the US government be successful at legislating against it by demanding backdoors. Yes, ISIS Is Using Encryption -- But Not Very Well