how did this all come to light? >> horrible news for shoppers especially if you were in target during those days. a security blogger got a tip. now the secret service are investigating. speaking with security researchers i know they said the hackers probably hacked the software behind a point of sale device. when you go and you swipe your card they probably hacked the software because it was a very large scale hack. you know, talking to folks at target they are in crisis mode right now trying to figure out what exactly happened. >> i do all of my shopping in target included online. i am not to be concerned about this if i used my credit card online with target? >> if you used your credit card online i would still check but they're saying this happened in stores. this happened at that point of sale system and that is something to note. so online shoppers should breathe easy right now i would say. >> reporter: effectively what are people in the industry saying about this? this is not the first time i've heard this happened but it is a panic when you start to hear