Initially, al Qaeda type groups reported is using steganography to hide messages in pictures and or movies. Through steganography it's an obfuscation method and cannot be considered encryption technology, it serves the purpose of hiding a message from plain sight which in turrt ensures relative privacy and is one of the main aims of encryption. This Modus Operandi was highly probable but...

$$ Has never really been proven

Defeats its own purpose

Has many advantages

Causes mistrust