If you use the same email everywhere, your email becomes your online security number.
And you shouldn't hand out your identity that easily.
Make sure to not use the same email everywhere. It can be as easy as having 1 email for family & friends (Facebook), 1 for professional (LinkedIn), 1 for non-essential stuffs (newsletter, e-commerce, etc). Better yet, you can also have a different email "alias" for each website using service like SpamGourmet, SimpleLogin (disclaimer: I'm its founder), AnonAddy, 33mail.
It's never too late to start protecting our online privacy. Your future self will be thankful :).