Some of you may have noticed recent developments in the news, where a prominent politician's Yahoo email account was hacked by a college student, with private emails splashed all over the web. Many people are pretty lax when it comes to security, and will do things like use the same password for multiple accounts (like a message board they visit and their email). Anyone who can gain access to the one password- such as an unethical administrator, or a hacker who tricks you into installing a keylogger or "trojan horse" program" that records your keystrokes. Really good ways to deal with that are to, obviously, not use the same password for things like email, boards that you visit, banks, and other important and confidential, and be very very careful with software that your download- plus watch out for the spam emails that get sent out asking for user names, or saying that there's a problem with your account.

There's also the problem where many people choose easy to guess passwords, or ones that can be cracked using dictionary or brute force attacks- so using

You'll be more secure and better off if you take these sorts of things into account, and here are some resources on phishing, hacking and social engineering:

http://en.wikipedia.org/wiki/Social_engineering_(computer_security)
http://en.wikipedia.org/wiki/Anti-phishing_software