With some of the issues around the Snowden leaks and what the NSA was doing I think have scared people around the world and I think in many ways rightfully so.

At Facebook, we build tools to help people connect with the people they want and share what they want, and by doing this we are extending people's capacity to build and maintain relationships.

We're really at this point where we can take a step back and think about the next big things that we want to do.

Of course the Silicon Valley is unique and Berlin is not yet comparable. But of all the different cities that are building a startup infrastructure, Berlin is the one with the most similar energy.

You can be so bad at so many things... and as long as you stay focused on how you're providing value to your users and customers, and you have something that is unique and valuable... you get through all that stuff.

The biggest risk is not taking any risk... In a world that changing really quickly, the only strategy that is guaranteed to fail is not taking risks.

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.