Credit card fraud is on the rise, with thieves stealing numbers and making millions of dollars of purchases before consumers even know there's a problem. The best way to prevent becoming a victim is to keep credit card information out of the hands of criminals in the first place.

A survey of law enforcement and private security agencies suggests three primary precautions consumers should take.

First, always know where your credit card is. With all the emphasis on Internet security flaws, many consumers forget that the easiest way to steal their credit card information is to take the information right off the card.

Always keep an eye on your card every time you use it, and get it back in your wallet as soon as possible. Never leave your credit card in plain view on the table, waiting for the waiter to pick it up.

Second, don't give your credit card number to just anyone. By all means don't use your credit card to purchase something from a telemarketer. If a telemarketer initiates a call, you have no idea who they really are. Don't give your credit card to anyone over the phone unless you initiate the call and you trust them.

Finally, never provide your credit card information in response to an email. Most spam emails are "phishing" scams designed to trick you into revealing credit card numbers and other sensitive data. It's never even a good idea to put sensitive information in an email to someone you trust, since email is not a secure form of communication.

If you suspect you are a victim of credit card fraud, contact the company that issued the card immediately and let them know.