I am chicken spit when it comes to credit cards.
About 3 years ago, someone stole my credit card number (I still had my card) and charged over $3000 on it. They even rented a car, which they never returned. I wasn't responsible for any of it, and my credit card company even waived the $50 responsibility. They told me that the number could have been stolen anywhere - even in a restaurant where they take your card and go away with it to run it on their machine. One other thing they told me: watch your card for charges at gas stations that don't belong to you. In order to see if the card they make works, they will go to a pay at the pump place and try it out. That way they don't have to face a clerk who might catch them...
Well, that's probably a good way to be. I use mine only once in a while these days.