You're watching, in real time, just how quickly your credit card number and other personal information can be stolen. So, what we're doing here is revealing one of the ways that you can become a... See More
You're watching, in real time, just how quickly your credit card number and other personal information can be stolen. So, what we're doing here is revealing one of the ways that you can become a victim. Reporter: We're at old man Rafferty's in new Brunswick, New Jersey, and watching along with us is Mario Armstrong, one of the country's foremost digital and technology experts. These skimmers are yw everhere. And so just like that, just one quick swipe, and all of the information that they need to commit fraud is done. Wow. Stored, right in here. Half a second. Half a second. Over 3,000 of these swipes I can hold into this before I need to dump it off. Reporter: And anyone can get these skimmers online. In just four days we got ours for just $169. People were advertising about these. Not only advertising about these but how to use them. How do you get that information out of this device on to your computer? There's a youtube video on that. Youtube, tutorials, how-to's on this stuff. It's happening everywhere. Reporter: And if it happened right in front of you, what would you do? Lauryn is finishing up her lunch and ready to pay the bill. And these guys have no idea our hidden cameras are rolling. I'm just gonna run to the bathroom. Do you mind watching my stuff? Thank you so much. And my drink, yes. Reporter: They notice right away that one of the belongings that she's left is her credit card. And they're not the only ones watching. Lurking a few bar stools away is Ben, another actor playing our thief. Within seconds he's got Lauryn's credit card and is quickly skimming it. Is that your card? Hey! What's that? Yeah. Hey! There's a young lady there. She asked us to watch her card Reporter: The entire restaurant is now on alert. Call the police! Reporter: Time to introduce ourselves. Hi, guys. Do you believe it? So you? Stepped up. Because? That's the right thing to do. People who want to make a difference can actually make a difference, like you just saw. Stopping the theft, it's a good thing to do. Reporter: It's something these women also understand all too well. You know what they're doing when they do that? They're getting the card number, right? He had a card reader on him, right? Yeah, yeah. Happens all too often. And it's a billion dollar industry now. Not when we're watching. Yeah. Reporter: But what if we switched it up a bit? Within earshot of these customers, we now have our thief try to convince the bartender, also an actress, to join in on the crime -- with a little incentive. I got 100 bucks here, I was going to see if you want to make some extra cash. Just hand me that credit card over there. That's it? Yeah. He's paying attention now. Reporter: While his friend doesn't realize what has happened, this man has a direct view of the entire transaction. And he still doesn't say anything. He watches but doesn't say a word. This is a problem, you know. It happens a lot. Credit cards get -- It happened to me twice, so I know. Really? What happened? They were, scanning the number at a place in Georgia, food shopping -- So you know what it's like. Why not sound the alarm? He said to her don't say nothing but I don't want to get involved in all of that stuff. None of your business? Well, you keep an eye open, you know? You have to. Reporter: This woman, out for lunch with a friend, spots Ben right away. Clearly, he's a little too close for comfort. They keep their eyes on him. Now, as quickly as he arrived, our thief is headed for the door. We let a few minutes pass, then we place a call to our actress, pretending it's her bank. Hello? This is she. What's the problem? Is there some issue with my card? Okay, thank you. Reporter: And, suddenly, it all makes sense to them. What did he look like? He had short, short dark hair. He reached over. Reporter: A pretty good description of our sneaky credit card skimmer. Will they be able to recognize the thief? We send Ben back in to find out. That was him. Excuse me, sir? Did you take this woman's card? Reporter: The commotion catches the eyes of this father and son eating at the other end of the bar. These ladies say you took my card and swiped it. Reporter: They try to question him, but, quickly, Ben is on the move. He's leaving now. Reporter: And that's when Evan Lipski takes matters into his own hands. Yo! Get the Back here! Where the You running to? Stand over here. What are you talking about? Why are you running out of here? You took the girls credit card. I don't know what you're talking about. Get back inside! What? You bet the cameras saw everything. We put them there. It's what we do. Oh, my god. I love this show. John Quinones. I can't wait to see this. You were lucky. I apologize. I thought I was going to get out here faster. I was like, wait a minute, dude. This is my time to shine. I'm small but I'm not afraid of anybody. Thanks for doing the right thing. Why is it important to be involved? That guy taught me. The takedown from this scenar scenario, when it comes to the credit cards, you can never be too vigilant.
This transcript has been automatically generated and may not be 100% accurate.