You can’t have privacy without security, and I think we have glaring failures in computer security in problems that we’ve been working on for 40 years. You really should not live in fear of opening an attachment to a message. It ought to be confined; your computer ought to be able to handle it. And the fact that we have persisted for decades without solving these problems is partly because they’re very difficult, but partly because there are lots of people who want you to be secure against everyone but them. And that includes all of the major computer manufacturers who, roughly speaking, want to manage your computer for you. The trouble is, I’m not sure of any practical alternative.
–Bruce Schneier on the “everyone else” problem.