The main Facebook usage is so big. About 20 percent of the time people spend on their phone is on Facebook.

People are learning how to use the site and what's OK to share. As time goes on, people will learn what's appropriate, what's safe for them — and learn to share accordingly.

When I started Facebook from my dorm room in 2004, the idea that my roommates and I talked about all the time was a world that was more open.

The thing that we are trying to do at facebook, is just help people connect and communicate more efficiently.

Facebook is really about communicating and telling stories... We think that people can really help spread awareness of organ donation and that they want to participate in this to their friends. And that can be a big part of helping solve the crisis that's out there.

Really, who you are is defined by the people who you know - not even the people that you know, but the people you spend time with and the people that you love and the people that you work with. I guess we show your friends in your profile, but that's kind of different from the information you put in your profile.