Number one with a bullet: your email account is a de-facto master password for your online identity. Most -- if not all -- of your online accounts are secured through your email. Remember all those "forgot password" and "forgot account" links? Guess where they ultimately resolve to? If someone controls your email account, they have nearly unlimited access to every online identity you own across every website you visit.

If the Sarah Palin email hack taught us anything...

Coding Horror: Please Give Us Your Email Password