But this morning, at a small office in Mountain View, California, three guys made the scope of that enormous debate look kinda small. 

Mountain View is home to WhatsApp, an online messaging service now owned by tech giant Facebook, that has grown into one of the world's most important applications. More than a billion people trade messages, make phone calls, send photos, and swap videos using the service. This means that only Facebook itself runs a larger self-contained communications network. And today, the enigmatic founders of WhatsApp, Brian Acton and Jan Koum, together with a high-minded coder and cryptographer who goes by the pseudonym Moxie Marlinspike, revealed that the company has added end-to-end encryption to every form of communication on its service.