Extreme online security measures to protect your digital privacy – a guide

Mark Zuckerberg uses tape over his webcam. Even if you're not worried about industrial espionage, there's no such thing as too much security

Outlook and other email clients let you install a personal security certificate, which you can use to encrypt email so that only trusted recipients can read it, or digitally sign your messages to prove that they came from you. You can get your own certificate from comodo.com and it doesn't cost a penny. The catch is that your recipients will need to be using a compatible email system - if they're using Gmail on their smartphone, they'll just be annoyed when you keep sending them unreadable strings of garbled data. "It also means you've got to protect your laptop," points out Tony Anscombe, security "evangelist" at the antivirus firm AVG. "If your laptop's stolen and your password is written on a Post-it note on the screen, then what's the use of the encryption?"