One time in Albuquerque, I interviewed for a job with the fraud
division of a credit card company, and as part of the interview they had me
listen to some calls with one of their employees. One of the
most common indicators of fraud–a few bucks of gas, then a big-ticket
item. Some credit card companies will freeze your card if they see that
pattern, forcing you to call in and verify that you made those purchases.

Stolen cards are on a “time limit”–the time from which the thief acquires
it, until the time the victim figures it out and cancels it. So the thief,
having acquired a new card (or just a new number, sometimes), will go to a gas
station and buy a few bucks of gas. If the card fails, he knows it’s already
dead to him. But if the card works, he races to a Best Buy to get a plasma TV
before the cardowner realizes what’s happened. The reason gas stations are so
popular for the “test run” is that they’re more anonymous, no one asks for ID,
and the thief can make a quick escape if needed.

There were other indicators that fraud might have happened, and the guy I was
watching showed me a few of them. (I can’t remember now; they were pretty
obscure.) But part of his job was to make outbound calls when there was
suspicious activity on an account. The calls all went something like this:

Mark: Hi, I’m Mark with [major credit card company]–
Customer: Oh, hey, it’s dinnertime, can’t talk.
Mark: *speaking quickly and interrupting before they can hang up* Fraud
division, ma’am, I’m not selling anything. I’m calling about the [type of
card] you have with us. We have seen some activity on the account that might
be fraudulent. May I ask you about it?

Customers, once they figured out that this was important, were really nice and
helpful for the most part. One person was suspicious that Mark was who he
claimed to be. Mark said it was smart to be skeptical, but to please call the
number on his credit card statement and ask to be transferred to the Fraud
Prevention department. During the half-hour I saw, he talked to a woman
who had just purchased a cello for her daughter, which is why there was a
sudden burst of activity–she was really glad to know someone was monitoring
this. And a businessman who was very terse, and clearly thought the credit
card company should be psychic and know that he went to France for two days.

It was really interesting.

And on a related note: If you’re ever a victim of identity theft, Privacy Rights Clearinghouse has a great resource telling you what steps to take to restore your good credit.