https://www.youtube.com/watch?v=rB9L1PD7Cpo
Go to 4 minutes into that video. It's his first interview post-reveal, in Hong Kong.
"Beyond that we've got Prism, which is a demonstration of how the US Government co-opts US corporate power to its own ends. Companies like Google, Facebook, Apple, Microsoft, they all get together with the NSA, and provide the NSA with direct access to the back ends of all of the systems you use to communicate, to store data, to put things in the cloud. And even just to send birthday wishes and keep a record of your life. And they give the NSA direct access that they don't need to oversee so they can't be held liable for it. I think that's a dangerous capability for anyone to have, but particularly for an organization that's demonstrated time and time again that they'll work to shield themselves from oversight."
Do we know everything now? Certainly not. NSA has resources that nobody knows about and I'm 100% certain that they have direct access to your data in ways that nobody has ever imagined.