I use Firefox mostly. When I double-click on the CVV2 field, the value that I used the previous time appears. The same applies to all the other Credit Card fields (number, name, address, etc). While this is great from a usability perspective, it's bad from a security point-of-view. A casual user in an Internet cafe scenario could easily get a list of valid credit cards by just double clicking on these fields. The Expiration Date is the only field which is not prefilled.
To prevent this from happening on your website, make sure to set the AUTOCOMPLETE field to OFF. You can do this at the HTML field or form level:
- <INPUT NAME="name" AUTOCOMPLETE=OFF >
That's Tuesday's Top Tip #1