They can scan credit cards that are still in your wallet if they have a RFID chip and if they can get close enough to you--which can't be that hard at a crowed bourse table.
It may only be a coincidence but on 8-20-12 I had a fraudulent $1,400 Internet sale charged on the card I used in Philadelphia.
It's more widespread than just the ANA show. I think because of all the coin peeps getting their CC hacked (many didn't go to Philly) it could be Paypal, US mint, or Ebay.
Last week my Grandfather had his credit card used for a fraudulent charge of $1000. And he's been ordering a lot from the Mint and eBay lately.
This is not my Ebay or normal travel card. I used this card specifically for the Philadelphia trip. Eight days later, a fradulent charge was reported to me. Like I said, it may simply be a coincidence.
