Facebook has finished rolling out Secret Conversations to their billion-or-so users. It is the biggest end-to-end encrypted messaging network on the internet. Facebook forces you to choose to opt-in to Secret Conversations each and every time. You can even set a timer on the conversation, deciding how long each message will remain visible inside the chat service. If your friends arent running the latest version of the Facebook Messenger app youre not going to be able to have a Secret Conversation with them.”]