Can Zuckerberg really make a privacy-friendly Facebook?

After building a social network that turned into a surveillance system, Facebook CEO Mark Zuckerberg says he’s shifting his company’s focus to messaging services designed to serve as fortresses of privacy.

Instead of just being the network that connects everyone, Facebook wants to encourage small numbers of individuals to carry on encrypted conversations that neither Facebook nor any other outsider can read. It also plans to let messages automatically disappear, a feature pioneered by its rival Snapchat that could limit the risks posed by a trail of social media posts that follow people throughout their lives.