Facebook is inherently viral. There are lots of sites that include a contact importer, and for lots of them it doesn't really make sense. For Facebook it fits so well. It wasn't until a few years in that we started building some tools that made it easier to import friends to the site. That was a huge thing that spiked growth.

When I'm talking to groups that are all men, we talk about how the masculine role limits them. They often want to talk about how they missed having real fathers, real loving, present fathers, because of the way that they tried to fit the picture of masculinity.

The most terrible job in warfare is to be a second lieutenant leading a platoon when you are on the battlefield.

It is the failing of youth not to be able to restrain its own violence.

Setting an example is not the main means of influencing another, it is the only means.