Never use the same password for multiple sites. Minimize the chance that a hacker who broke into one account can gain access to your other online accounts.

Create and use separate e-mail addresses. Specific e-mail accounts for specific shopping sites—say, "MyAmazonAccount@gmail.com"—will limit your data exposure when a particular online retailer gets hacked.

Never use any part of your name or any other easily guessed word in your password.

Use a strong password, including a mixture of letters, numbers, and special characters. Substituting numbers for letters might help you remember your login--"pa55w0rd" instead of "password," for example. And some websites allow the use of symbols such as ! and #. For more password advice, see "How to create a strong password (and remember it!)."

Verify that the site you're doing business with is a known and trusted retailer.

Happy Cyber Monday- Mark