I have two pieces of advice:
- Watch those credit card statements closely! If you see something odd, report it immediately. Better yet, check your card status weekly or more regularly using your bank's online facilities.
- Set aside a single, low ceiling credit card solely for online purchases. Use other cards for "bricks and mortar" purchases. That way, if my "b&m" card receives a fraudulent charge, I know it wasn't a result of online fraud.