The killer of Russian Ambassador to Turkey Andrey Karlov was reportedly a user of Bylock, an encrypted communication application used as an internal form of communication among Gülenist Terror Group (FETÖ) members.

It was reported by several Turkish dailies today that Mevlüt Mert Altıntaş, who assassinated the Russian envoy Andrey Karlov late Monday in Ankara, had Bylock on his personal mobile phone, however he was not an active user, but only was informed from internal communication between FETÖ members via the application. Altıntaş was also allegedly directed by FETÖ to become a policeman when he was in high school in the province of Aydın.

The testimonies from Gülenists in the bureaucracy detained after the July 15 coup attempt pointed to the prevalence of the use of apps. Prosecutors say Bylock was popular among Gülenists for secretive communications between 2013 and 2015, and after 2015, the terror cult turned to Eagle IM, which offers "256-bit end-to-end AES encryption" for its users, according to the description of the app in the Google Play Store. The app's developers also promise protection from "Man In The Middle" attacks or hacking into chats between two people that enables message altering by one of the two parties. Similarly, Bylock was offering an eight-digit password for users and highly secure encryption.