A verification of security is always based on an attacker model. There is no general security. The actual point is not security, but trust and certainty. Being

A verification of security is always based on an attacker model. There is no general security. The actual point is not security, but trust and certainty. Being Open Source does not change whether some messaging app is secure or not. It changes our knowledge about the code. It also makes me have a little bit more trust in some company for revealing their stuff. Even if WhatsApp open-sources the clients, there is still the problem of US jurisdiction. NSA can force them to silently including a backdoor or send everything to NSA-servers. Trust is a difficult thing.