The real question for me is, do people have the tools that they need in order to make those decisions well? And I think that it's actually really important that Facebook continually makes it easier and easier to make those decisions... If people feel like they don't have control over how they're sharing things, then we're failing them.

I look at Google and think they have a strong academic culture. Elegant solutions to complex problems.

On engagement, we're already seeing that mobile users are more likely to be daily active users than desktop users. They're more likely to use Facebook six or seven days of the week.

And connected is helping people stay in touch and maintain empathy for each other, and bandwidth.

In a world that's changing so quickly, you're guaranteed to fail if you don't take any risks.

Some of the best ideas throughout the company's evolution have been from places all throughout the company whether it's an engineer or someone on the customer support team. Just different areas around the company.

It only took me two weeks to build the first version of Facebook because I had so much stuff before then.