"When I got started in my dorm room at Harvard, the question a lot of people asked was 'why would I want to put any information on the Internet at all? Why would I want to have a website?'
"And then in the last 5 or 6 years, blogging has taken off in a huge way and all these different services that have people sharing all this information. People have really gotten comfortable not only sharing more information and different kinds, but more openly and with more people. That social norm is just something that has evolved over time.
"We view it as our role in the system to constantly be innovating and be updating what our system is to reflect what the current social norms are.
"A lot of companies would be trapped by the conventions and their legacies of what they've built, doing a privacy change - doing a privacy change for 350 million users is not the kind of thing that a lot of companies would do. But we viewed that as a really important thing, to always keep a beginner's mind and what would we do if we were starting the company now and we decided that these would be the social norms now and we just went for it."
In light of today's NSA revelations from How we know the NSA had access to internal Google and Yahoo cloud data.