Quote from: Bornakk (Source)

Account security is very important to us. As we have recently seen a rise in the number of compromised World of Warcraft accounts, we recommend you to take a few moments to read these tips to help protect your privacy and ensure your security.

• Verify that your email address in Account Management (http://www.worldofwarcraft.com/account) is current. You can see your address on the right side of the Account Management page and change it with the “Change Contact Info” button.
• Make sure your operating system, web browser, and other software is up-to-date with the latest patches and security updates.
• Scan your computer for viruses, Trojans, and key loggers.
• After doing this, we highly recommend changing the password on the account to a brand-new, unique one, and making sure to keep this password private.

These simple steps can go a long way in maintaining account security. If you are seeking an additional layer of security, consider purchasing the optional Blizzard Authenticator, available at the online Blizzard Store (http://www.blizzard.com/store/details.xml?id=1100000182). For more security tips, please visit our World of Warcraft Account Security page (http://us.blizzard.com/support/article.xml?articleId=20572&rhtml=true?rhtml=y).

We hope you have a happy and safe holiday season!