Z:gnu-www-ja-google-engineering-talk--64db1a-And sometimes they have actual/en

And sometimes they have actual back doors. For instance, Windows XP has a back door: when it asks for an upgrade, it tells Microsoft who you are, so Microsoft can give you an upgrade designed just for you. And this upgrade could have secret accounts, it could have special spy features, it could just refuse to work. And there's essentially nothing you can do. So that's the back door that Microsoft knows about and we know about.