Transcript for What Would You Do: Teen boys selling fake event tickets
"What would you do?" Continues. Yo, show me the tickets. Yeah, I printed them out this morning. They look pretty real right? Yeah, these are legit. Man, I'd have no clue they're fake. Oh, quick, put those away. Here's our first sucker -- I mean, customer. Hey, are you the guy I've been emailing with about the tickets? Yeah, do you have the money? Here you go. I'm so excited. It's been sold out for months. It's one of the oldest tricks in the book. A scammer tricking fans into shelling out real money for fake concert tickets. If you saw a fraudster about to rip off an unsuspecting buyer, what would you do? I'm so happy you sold me these tickets. Yeah, I'm pretty happy too! Reporter: Our hidden cameras are rolling at Jean Jacques in pleasantville, New York, as Marc and dom openly discuss their scam. This is crazy. Let me see them. Right away, this woman starts listening in on their plan. How many did you make? About 500. That's so bad. This girl might be here like any minute. So do you mind not being here when I talk to her because it might sketch her out? Yeah, yeah, yeah. Thanks, man. And she's got a pretty good ticket to watch Lila getting swindled. I can't believe you had tickets. Is there any way you can get more? How many more? I have like 2 other friends who really wanted to come as well. I could get you more tickets for sure. I could call somebody but do you have cash on you? When our con man steps out to use his phone that's her call to action. I think whatever you're buying from him, he's ripping you off because he pulled out a huge handful of these tickets. Really? Yes. I don't know. I don't know what you're doing. I'm a stranger, but he had a stack like that. I was just about to buy two more. Reporter: Now this father, sitting with his daughter, speaks up, but he's not so sure Lila is getting ripped off. I overheard some of the conversation too and it didn't seem like they weren't real. So when our scammer returns, he decides to investigate. I just got off the phone, we're good and I can get the ticketing for you. Reporter: And he puts him on trial. These don't seem real to me. It feels like you just printed it on card stock. I wouldn't rip you off. I could prove it to you. I can get you tickets to other shows. Reporter: Time to render the verdict. Hi there. Excuse me, sir. I am John Quinones. Oh, no way. We do a show called "What would you do?". Yeah, I have seen it. You know the show? Yes. We watched it together. Oh, that's great, you sounded the alarm, right? I was just really concerned that she was going to get something that, that wasn't real. Why is it important? If you see something that doesn't seem quite right, you should let somebody know. I would hope that somebody would tell me, if I was in a similar situation. Reporter: Back in our cafe, our con artists are back at it. These real? Yeah. Come on. I printed them out this morning. Yo, man you've got to get me in on this. And pretty quickly, she figures out what they're planning. Here just sit over there for a second. About to get bamboozled -- So how much is it again? $450? $450? Okay. So I'll take 50 bucks off, it's not really giving me much of a profit but uh I'll do it for you, you seem nice. Aw. Thank you. She is clearly concerned, but remains silent. I'll just be one minute. Until she's sure Lila is alone. Then she tries to warn her. You're buying tickets for something? Yeah for the garden state music festival. Be real careful. He was talking to another fellow and they got real excited about whatever price you're paying, and then the other guy went to the other table before you came back. I really wanted to go and I couldn't find the tickets anywhere else. And he said he could get more for me. And I couldn't find them anywhere else. Just be careful. If you couldn't get them online how is it he's got them? Hi ma'am, how are you? Oh, my god. I don't believe this. This happens all the time. And you tried to tell her? I have got kids older than her. And I was like, "I don't want anyone taken advantage of her." Our swindlers sell their fake tickets all day long. I mean I've already made a couple grand. At first, this man jokingly calls them out. Let me know what tickets you're selling so I don't buy them. But on his way out, he offers this to Lila. Miss, are those real tickets? I think so. And this guy, he's got their number. I saw you had a whole wad of them. And warns them he's going to move their show to a new venue. If you're selling illegal tickets, there's a police station up the street. What was going thru your mind? The age we live in that you can print tickets. Anybody can easily can do it. Anybody can do it can print them up. We're rolling one last time. Can I look at the tickets? Yeah, did you bring cash? Yeah, I brought the money. I never really bought tickets from guys online, but I trust you. It must be pretty legit. I wouldn't rip you off. Oh no? Even these young girls seem to sniff out he's up to no good. So you don't have anymore for this one? Well, you know what? I could make a phone call for you. My buddy who's taking me to the city might have some in his car. When Lila is left alone, Isabelle wilder and her daughters come to her rescue. Can I just tell you something? I'm sorry? When I came in he was asking people if the tickets look genuine. Oh. And I don't know, I got very suspicious. Like asking, do these look real? What did he say? I think he asked, do these tickets look real? And now it's time fortous get real and tell this mom and daughters, a real crime fighting team, that's it's "What would you do?". Hi, I'm John Quinones with the TV show "What would you do?." You were great. You really blew the whistle on these guys. I thought he was trying to steal her money, so I was scared for her. I was like scared and just like, "Oh no, what if she falls for it"? And she almost did, but then your mom spoke up. Are you proud of your mom? Why is it important to speak up like this? Well, if somebody is doing
This transcript has been automatically generated and may not be 100% accurate.