Late on the evening of January 11, 2013, someone sent me an interesting email. It was encrypted, and sent from the sort of anonymous email service that smart people use when they want to hide their identity. Sitting at the kitchen table in the small cottage where I lived in Berkeley with my wife and two cats, I decrypted it.

"Micah," the email read, "I'm a friend. I need to get information securely to Laura Poitras and her alone."