Once your account is secure, it's good to establish habits which can help you keep it this way. While there are many methods by which to maintain the security of an account, here are some tips to get you started:
- Complete operating system updates regularly (preferably as they become available).
- If you use Firefox, install NoScript and run it consistently while browsing.
- Run antivirus and anti-spyware scans weekly.
- Never willfully share your login and password. Even friends, family, and significant others can place your account at risk.
- Be aware of "phishing" emails and websites, and do not to respond to any invalid requests. Remember that a Blizzard Employee will never ask for your password.
- Monitor the availability of your email address and do not post it publicly.
Additional information can also be found here:
http://us.blizzard.com/support/article.xml?articleId=20572