Each year, millions of dollars are lost due to fraudulent use of charge and credit cards.
Reduce the risk of you being the victim by following these basic guidelines

• Don’t leave your credit cards unattended.
  If you usually leave your cards in the car be aware that a very high proportion of credit cards are stolen from motor vehicles. Also always keep your cards with you at work, there are more credit card thefts in the workplace than in any other single location. As a general advice never carry credit cards you don’t use.
• Always check your card when returned to you after a purchase.
  Remember to sign credit cards, in ink, as soon as they arrive and then every time you use it make sure that the card that is returned to you is your card.
• Do not provide account data to someone over the phone
  If you really have to do it make sure you are the one who initiated the call and the company you are talking to is reputable.
• Take good care of your credit card receipts
  They may include your credit card number so never toss them in a public trash bin. You’ll need that receipt later anyway to tally things up when your statement arrives. When you eventually decide you don’t need them anymore shred them.
• Shred all documents that might include your credit card number
  To prevent identity theft shred them before disposing of them - old slips, credit card statements, bills, anything.
• Never respond to an e-mail asking for your number
  No matter how official or legitimate the mail looks, this is one of the most popular fraudulent activities.
• Review your monthly statement
  Do that as soon as it comes and report any problems right away. To insure your rights, follow-up by filing a written complaint form.
• Always use the credit option on a bank card
  If you are given the choice between credit or debit always use credit as this may prevent the skimmer device from accessing your four digit pin number.
• Apply for a Photo Credit card
  The picture as is added security measure which could help your identity from being impersonated in merchant establishments.
• Keep a record of your card numbers
  Record their expiration dates, and the phone numbers and addresses of each creditor, in a secure place.

For more information on this subject you can refer to
http://en.wikipedia.org/wiki/Credit_card_fraud or
http://www.ckfraud.org/credit_card.html