this is "nightline." tonight, undercover mom. posing as children. >> are you happy, pretty girl? >> the teen determined to take down potential sexual predators lurking behind popular apps. >> he want a live photo. >> preying on the most vulnerable. now the surprising discovery. >> it's astounding and stomach turning. >> reporter: and candid confessions. justin bieber's season of self-reflection. >> i was waking up, and the first thing i was doing is popping pills. >> the incredible journey of highs and lows. how his wife hailey helped him find his way. >> no matter what his outcome

was going to be, he was going to be somebody i loved. >> but first the "nightline" five. actions speak louder than words. she was a school teacher. my dad joined the navy and helped prosecute the nazis in nuremberg. their values are why i walked away from my business,

took the giving pledge to give my money to good causes, and why i spent the last ten years fighting corporate insiders who put profits over people. i'm tom steyer, and i approve this message. because, right now, america needs more than words. we need action. good evening. thanks for joining us. tonight, the undercover mom going to extremes to flush out potential sexual predators. posing as a teen and even a tween with alarming results.

exposing the dark side of popular kids apps. abc's tj holmes takes us behind-the scenes of the elaborate operation to track and take down those lurking off-screen. >> all right, i'm ready. >> reporter: you're watching as slone, a suburban mom, transforms herself to pose as an underage girl online. for her safety, we won't show you her face. we won't tell you her real name. >> because i am 37, i have these lin lines right here around my face. and younger kids don't have that, so we will use gravity to help. i'm going to lean back like this. >> reporter: slone is the head of a special project at bark to track kids' social media use. >> children are being methodically groomed and abused

in a matter of moments on platforms that should be a lot safer for them. we are finding is that it's not just a random occurrence. >> oh, i think we got it. okay. this still needs to be photo shopped, but i think that's one. >> reporter: part of the mission, so show how predators use social media to target young children. >> we can liquefy it and pull it back. but i think it's the one. >> reporter: it's every parent's nightmare at a time when almost a third of teen girls have reported receiving unwanted explicit images. we're behind the scenes, as the bark special projects team launches an undercover operation, creating online personas, for a 11-year-old and a 15-year-old. >> so we're going to dress these two rooms. this is for our 11-year-old persona, and this room is our 15-year-old persona's.

>> reporter: going as far as dressing up bedrooms to make it all look ah then tech. >> sometimes we'll display her training bra. >> reporter: graphic artists photo shop slone to make her look like a tween and a teen. >> here's 11-year-old bailey. and there is 37-year-old slone. >> how do you all do that? >> a lot of work. >> reporter: computers and phones are set up with the fake social media accounts. >> it's coffee cups, puppies, flowers, normal just teen and tween expressions on social media. what we've been able to demonstrate with these is regardless of how innocuous content may be, they're still susceptible to being targeted by really terrible people. >> reporter: 7:00 p.m., time for the teen to go live with new photos. >> so right now, we posted just seconds ago. and now frankly, it's just a

waiting game. >> reporter: what usually happens? >> we're testing the waters to the full-blown explicit content, photos, videos, texts, it's astounding and stomach turning. >> reporter: slone takes one of 15-year-old libby's accounts. >> reporter: you're giving them every opportunity to stop. >> law enforcement shares the parameters they abide by. >> reporter: already, someone has sent an explicit, nude photo. >> i just imagine being a 15-year-old and not really knowing what's going on. it's something that these people seem to really know how to exploit. >> reporter: just a few minutes later on another account. okay, tell me what's happening. >> he wants a live photo. >> reporter: the pretend 15-year-old receives a request for a selfie from someone who claims he's a teen too. >> reporter: mind-boggling. and then she's asked for a bra pic. another conversation turns sexually explicit. >> can you give me some motivation. >> reporter: but what happens to

the 11-year-old persona, bailey, is even more disturbing. someone claiming to be 26 sends a photo. >> are you happy, pretty girl? >> reporter: then texts, you owe me more, asking a photo of your tummy and beautiful chest. slone instead sends a g-rated photo. what happened? >> he wanted a replay. it's like he wants to replay it. >> reporter: this time he'll be able to keep the image? >> that's right. >> reporter: she sends the photo again. the person on the other end is persistent. after ten messages. >> this language is really realy indicative of someone who's grooming. i really don't want to share you. that is really controlling language, and just as a reminder, he started talking to her half hour ago. >> reporter: so you're reminding him of your age. >> that's right. >> reporter: you're giving him. >> i'm in sixth grade. i'm just going to pop those reminders in there. do you need a quick sanity

check, remind yourself that you're talking to a 11-year-old here, but he's doubling down. >> reporter: bark turns over these potential predators to the center for national missing and exploited children and say they've reported over 300 cases to enforcement. >> they are sometimes very urgent and time sensitive. >> reporter: some of those tips investigated by investigators. >> no matter where your children are, predators are going to go to. it's increased dramatically. >> reporter: he runs new jersey's crimes against children task force, identifying 3 pedophiles. >> we've arrested schoolteachers, police officers. the reality is, these are your next door neighbor. >> reporter: he worked with federal and state agents in a major undercover sting operation that led to the arrests of 19 men. >> they were allegedly looking to have sex with underage

victims. >> reporter: bark also has an app that parents can use to monitor kids' phones. using the app has led to arrests like this one in florida last year. parents of a 16-year-old girl were alerted when she received nude photos from a 25-year-old man. he has pled not guilty and is awaiting trial on two felony charges of using an electronic device to seduce, solicit or lure a child and cruelty toward a child. for the bark team, the work can be draining. >> i'm an adilt, and it's upsetting to me, traumatizing to me, and then i put myself in the shoes of a 11-year-old that doesn't have the tools to cope, doesn't have someone to talk to, that's devastating. >> reporter: have you had to go talk to somebody, a professional yourself about what this is doing to you. >> oh, absolutely. we are a close-knit team. everyone's allowed to take a break and talk with a therapist. >> reporter: a moment of

reflection and back to work. often through the night. >> we have good days and bad days. what is a good day at work for you? >> if we can be a part of eradicating child sex abuse through awareness, making platforms safer, that's a good day at the office. our thanks to tj. up next, the change in season for justin bieber. how faith and a new wife helped turn his life around. ♪ oh, like baby, baby, baby, oh, ♪ ♪ thought you'd always be mine tender wild-caught lobster, dig in to butter-poached, fire-roasted and shrimp & lobster linguini. see? dreams do come true. or if you like a taste of new england without leaving home, try lobster, sautéed with crab, jumbo shrimp and more, or maybe you'd like to experience the ultimate surf and the ultimate turf... with so many lobster dishes, there's something for every lobster fan so hurry in and let's lobsterfest. or get pick up or delivery at redlobster.com imagine.

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mr. michael bloomberg is here. vo: leadership in action. mayor bloomberg and president obama worked together in the fight for gun safety laws, to improve education, and teens gain the skills needed to find good jobs. obama: at a time when washington is divided in old ideological battles he shows us what can be achieved when we bring people together to seek pragmatic solutions. bloomberg: i'm mike bloomberg and i approve this message.

it's justin bieber like you've never seen him before. revealing in a new youtube docu-series why he took a break from music nearly three years ago. the pop star breaking his silence. how his faith and the love of his life brought him back from a dangerous time in his life. >> there was a time in my life where i was popping pills, you know, shrooms, everything. it was just an escape for me. >> reporter: a candid justin bieber, opening up on camera for the first time about his past struggles. >> you have all these people around me just kind of hanging on, wanting stuff from me, knowing i was living this lifestyle that they also wanted to live, drinking, smoking. >> reporter: in his new youtube docuseries, justin bieber, seasons, you get a glimpse of the turmoil in his personal life. >> as humans, we go through so many ups and downs. so many good seasons, bad seasons. >> pop superstar justin bieber,

arrested at miami beach overnight. >> charged with dui, resisting arrest. >> reporter: all of which says he was led to put his career on hiatus. >> the first thing i was doing was popping pills and smoking a blunt. >> nothing was off limits. >> reporter: the director follows the pop star on his journey to sobriety. >> he was willing to go there, and he said to me, there's power in weakness. >> reporter: all while bieber works on his first studio album in nearly five years. >> i love to see him do what he is so good at. >> whee! >> reporter: bieber's wife, model hailey baldwin by his side, offering a rare look at the couple in their day to day lives. >> she makes everything better. >> vogue described hailey as a super ego to justin's id. >> reporter: the show also touches on bieber's recent diagnosis with both lyme and epstein bar diseases.

this week becoming the first artist to reach 50 million subscribers. a full-circle moment, since it was that platform that helped launch his music career as a tween. when covers like this one, chris brown's "with you" caught the eye of mogul scooter braun in 2008. "nightline's" cameras were back stage in those early days as bieber fever swept the nation. >> i feed off the fans' energy. if they're screaming really loud i get all pumped up. it's really exciting to me. >> from the beginning, justin bieber has been someone who looked like he was cooked up in a factory to make the perfect male teen idol. at the time, he first became publicly prominent was unusual in that he didn't have a tv show on nickelodeon or the disney channel or mtv to kind of prop him up. >> reporter: like so many child stars, his coming of age was

four the world to see. >> being a young star is like taking a tall ship through the biggest storm you can imagine. it will test everything. it will take the weakest, most vulnerable parts of who you are and it will expose them to the greatest stress. >> reporter: his blunders were pub lib. in 2014, the young star's behavior triggering multiple tabloid-filled run-ins with the law. including a dui arrest. >> remember shall everybody loves young teen stars because they are compliant. then one day they are not compliant. >> reporter: despite the controversies, bieber launched his "purpose world" tour in 2015, 150 concerts across 40 countries in six months. but what fans saw, a visibly exhausted pop star on stage. bieber abruptly cancels the final 14 shows, posting on instagram, me taking this time right now is me saying i want to

be sustainable. i want my career to be sustainable, but i also want my mind, heart and soul to be sustainable. >> he didn't want to tour anymore. and he more or less dropped out of sight. >> reporter: in the new docuseries, his creative team talks about that tumultuous time. >> i freaked out when justin canceled the tour. performing is the thing he loves most in the world. for him to say he didn't want to do it, i knew it had to be pretty serious. >> it got scary. i basically said to myself, god, if you're real, get me through this season of stopping these pills and stuff, and if you do, ail do t i'll do the rest of the work. >> reporter: in search of something deeper, he seeks spiritual guidance. >> he seeks counsel with lentz. >> justin is a friend of ours. he loves the lord with all his heart. there was a night when he wanted to renew his faith and get

baptized again. >> reporter: hailey says their relationship only got serious once he chose to be sober. >> he was the first person i ever had real feelings for. when things kind of went south for an a little bit and we went our separate ways, i just knew that no matter what the outcome was going to be, he was going to be somebody that i loved for the rest of my life. >> just the idea of stability is something that i really never had growing up. and it's something that i've always really wanted. >> reporter: she believes her husband's addictions were a byproduct of his early fame. >> i think when you take somebody very, very young and they start to get horrible, crazy, crippling anxiety and it goes undiagnosed, and you don't know what it is that you're feeling, you start to self-medicate, because it makes you feel better. >> when my friend justin bieber came all the way -- >> reporter: his public turning point came at a surprise appearance at coachella in 2019,

ending his hiatus by joining ariana grande on stage to sing "sorry." alluding to a comeback, as he left the stage. >> as he was walking off stage, he said i need to get back out here. >> i want you to schedule me. i want to go to the studio, and i want to dance, and i want to go to the gym. and i want vocal warmups in there. he wanted me to build him a rolling eye continue rashy like i do when he's working. >> reporter: which is what he says he's doing now, spending most of the time in the studio, preparing his new album "changes". >> every time you come around i get it done. >> reporter: the cameras rolling through the entire creative process. >> my perfectionist? oh, yeah. ♪ i think for me, having been always so polished and perfect, and everything needed to be so perfect, and i felt like i had

to worry about literally everything. don't touch your face that way. don't touch your hair. you're ruining, you got a stain on your shirt, that's why these little things like, i really just don't even want to make that a huge deal. >> the new record is obviously very much about justin's relationship with hailey. >> it's really hard being the muse of the whole album. just kidding. don't put that in there. >> my life is changing a lot. getting married. getting back in the studio, talking about getting married. writing about the process and being creative with being in this new chapter and being happy about what i'm doing and not like, i don't know, being in a good headspace. >> reporter: and in the final act of his comeback. bieber recently announcing he's going back on tour. >> i think justin can address the conflicts and challenges in his life and still be very appealing and very light. it is impossible not to root for that guy. >> we all have our individual pains and fears and anxieties. worries. i think that being human is

challenging for everybody. i think that we're all struggling to some degree. you can watch the docu-series on youtube now. we'll be right back. i remember thinking about things i did and wondering if that was the last time i was going to do that thing. i thought i'm not letting anything take me away from my family that loves me and needs me without a fight. , from my family that loves me and needs me it felt so different from any other hospital we'd ever been to. whether it be spiritual, physical, emotional, they take it all into consideration in healing you. infusion, imaging, everything is here. i don't have to go anywhere else. they create a treatment plan that's for you. they cared about my victories.

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i'm proposing big reforms like term limits... ...a national referendum... ...and ending corporate money in politics. as president, i'll declare climate change an emergency on day 1. and, use those powers to finally address the climate crisis. and, i've spent 30 years building a successful international business. so, i can take on donald trump on the economy - and beat him. i'm tom steyer and i approve this message - because there is nothing more powerful than the unified voice of the american people.

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so the stage is getting set for the final democratic debate before the new hampshire primary. my colleague, byron pitts is already there with a preview of the set. >> reporter: hey, we're at the scene of the democratic debate, just finished our rehearsal. look at this place. the team at abc news transferred, this is a hockey arena that they transformed into a spectacular studio for the debate. here's the podiums where all the candidates will be friday night. and hopefully, we'll see you then. >> we'll definitely check it out, byron, right here on abc. that's "nightline" for tonight, thanks for staying up with us u goodnight, america.

othroughout the country for the past twelve years, mr. michael bloomberg is here. vo: leadership in action. mayor bloomberg and president obama worked together

in the fight for gun safety laws, to improve education, and to develop innovative ways to help teens gain the skills needed to find good jobs. obama: at a time when washington is divided in old ideological battles he shows us what can be achieved when we bring people together to seek pragmatic solutions. bloomberg: i'm mike bloomberg and i approve this message. fisn't just about polar bears. we're fighting for our lives, we're fighting for clean air and clean water. that's why i wrote the law to send billions from polluters to