Use virtual numbers if possible If you have a credit card that allows you to generate a virtual account number, then do so for all your online transactions. You can set a spending limit and set it so that the number can only be used at a particular merchant (Citibank does this for example). This way if that number gets stolen, the thief will have a harder time trying to use it.
reply to StudioTech
Before signing up for Citibank's Universal Card Virtual Account Number (VAN) service, read the user agreement very carefully.
If your credit card # gets stolen, your liability under CitiBank's "0 liability" policy seems to be just that ($0) if it is reported to Citibank upon discovering it. I believe that Federal law also has a cap ($50?).
On the other hand, the VAN user agreement seems to make the cardholder responsible for any charges incurred due to compromise of their VAN userid/password (such as via keyloggers, shoulder surfers, et al). It may be that this liablity is also limited by the Federal law, but I Am Not A Lawyer so don't feel comfortable speculating/relying on that.