One of the most useful features on the Internet is auto-complete. Start typing in a search term, an email, or a name on Facebook, and the computer is going to guess what you're looking for based on what you've searched before. We've all seen how this can be a problem. Who hasn't had a friend stumble upon perverse sexual maneuvers or strange porn subgenres in your search history? If your girlfriend pops the first name of your cute new co-worker into your Gmail, she may be able to see all the e-mails youv'e sent back and forth, even if they are in the trash. Simply clearing your search history won't be enough. You've got to manage your email, social media, and your browser, because if your girl happens to search the right first letter, you could quickly find yourself searching for a new apartment.