Bank Info Security reports
on a wave of credit and debit card crimes against merchants and consumers across the U.S. According to the article:
multiple states are being struck concurrently by attacks that include skimming, point-of-sale swaps of terminals and possible hacking incidents of payment processing software.
Some of the incidents involved hackers stealing card info from internet servers. Note, it's usually easier to reverse fraudulent credit card purchases than debit card purchases. That's one reason to use credit cards for online purchases.