If you think yours was one of the 40 million credit or debit cards involved in a data breach at Target, security experts recommend a policy of watching and waiting: Watch the account you used at the retailer on a daily basis, and wait, because there's no telling when it will be tapped by thieves.
http://www.chicagotribune.com/business/yourmoney/sns-how-to-handle-targets-data-breach-20131220,0,3035149.story