How this works is, someone, somehow got all the CC info.
They likely break it off into chunks and sell those chunks to people. They buy 10, 25, 50, 100 card #'s. Likely half of those don't work (Card has been canceled already, etc) but the other half do work. These #'s are going to be random, and not likely in any order.
The person who bought the numbers has a machine that can re-program his OWN credit card. He flashes his card with your cards info. So when he goes to Best Buy, or whatever, he shows HIS CARD and HIS ID and everything looks legit. When he swipes and signs, it's YOUR # that pops up.
Newer retail stores have the checker enter the last 4 of the CC to make sure they match. If the customer suddenly decides they don't want the item etc, likely a fraudulent card. That's why you see lots of sales at smaller places, busy places, places that don't have the time/energy to check each transaction (Online works too usually, especially if they got the little 3 digit code).
So they'll use a card # until your bank realizes it's fraud and shuts it down. They go home, re-flash it with someone elses # and continue on their merry way.