Memories of a talk in grad school where we had a guest from Google (also an alum of the school) presenting. He had been with Google from early days and had a hand in their biggest products, including Gmail. It was a very good talk, and I don't mean to disparage it, but someone from the audience asked him a question about user privacy and he answered it by describing how good Google's security is. Like, he didn't quite see the difference between privacy and security. It was illuminating.