cbs news correspondent susan copen has what you need to know. >> reporter: we use smart phones for just everything from photos, text messages, to banking and shopping. >> it is a treasure trove for theft. >> reporter: at this computer laugh, professor anthony and his students were looking for information, left behind on cell phones. what did you find. >> we found a lot of text messages, conversations, personal items, even snap chat and things that you think are gone, they are not gone, we will find it. >> reporter: this damaged i phone, second one that they plugged in, turns out to be filled with illegal activity. >> that had a text messages of drug deals, prostitution and gambling. >> reporter: this phone didn't come with a battery but it did have its memory card, still included. so you are giving away. >> your life. >> reporter: your life. >> yes, and thieves trying to build a story around you so they can personally use it, open an account in your name, so they can just make a good story. >> reporter: using software that anyone can buy, professor and his students, scanned phones that

you may think you have cleared all your personal information but susan copen reports you could be leaving behind crucial data. >> reporter: we use smartphones for everything from photos and text messages to banking and shopping. >> it is a treasure-trove for identity theft. >> reporter: in this computer lab, at st. vincent college, professor anthony [ indiscernible ] and his students were looking for information left behind on cell phones. >> what did you find? >> we found a lot of text messages, conversations, personal items, even snapchat and things that you think are going to be gone, they're not gone. we'll find it. >> reporter: this damaged iphone, the second one they plugged in, turned out to be filled with illegal activity. >> it had text messages of drug deals, prostitution and gambling. >> reporter: this phone didn't come with a battery. but it did have its memory card still included. >> so you're giving away -- >> your life. >> reporter: your life? >> yes. >> i have had these people trying to build a story around you so they can impersonate you so they can open accounts in your

susan copen shows how you may be handing over your personal information to hackers, even if you think you cleared your phone. >> reporter: we use smartphones for just about everything, from photos, and text messages to banking and shopping. >> it is a treasure trove for identity theft. >> reporter: in this computer lab, professor anthony sarapilia, and his students were looking for information left behind on cell phones. >> what did you find? >> we found a lot of text messages. conversations, personal items. even snapchat and things you think are going to be gone, are not gone. we'll find it. >> reporter: this second iphone turned out to be filled with illegal activities. >> text messages of drug dealings, prostitution. >> i had thieves trying to build a story around you, so they can impersonate you. >> reporter: using software that anyone can buy, professor and his students scanned phones that were purchased from goodwill. >> everything, all makes and models from earlier samsung phones, to iphones. >> reporter: all of the phones were sold in bulk online. 25pounds of phones, purchased