There are virtually endless ways to hack debit and credit cards high and low tech. My business debit card was hacked a year and a half ago. The charge, which was small, was reversed and a new card was issued. But it is a lousy feeling when it happens and you don't have to use a card on the intertubes to be vulnerable. Security and anti-fraud measures by banks and issuers vary from paper thin to annoyingly robust.

Amex used to drive me nuts. In NYC, MetroCard machines are among the top favorites of card fraudsters. Every 2nd or 3rd time I'd use my Amex card to buy a pass, I'd be denied and would have to go topside to call Amex and assure them that it was me attempting to buy a MetroCard, and then wait 10 minutes for the block to be removed so I could buy my pass and be on my way.