If messengers are not the next big thing, then they are the current big thing. The great Electronic Frontier Foundation offers an overview / scorecard about messenger security and you can even learn about software you didn't know it existed. At least I didn't know many of the messengers in the list. While FaceTime and iMessage score pretty well, apps like Secret, Viber, Yahoo Messenger, Snapchat, Whats App and Facebook Messenger are not recommended. Best scores? Telegram does well, but winners according to EFF are SilentText, TextSecure, Redphone, ChatSecure+ Orbot and CryptoCat, Now try and find friends on these.