How much can a computer learn about your life?

How much does a computer know about your personal life?I don't think it's a good idea to say how much information a computer has about your every move, but we can take some precautions against being spied on.If you're not a fan of being watched, or don't trust computers to be able to tell you what you want to know, there's always the option of encrypting your data.But that's something that is more...