tonight on "nightline" -- underage and exploited. young american girls being bought and sold, not on the streets, but online. while web sites make millions. tonight "nightline" investigates backpage.com and the big business of selling girls. and feline fishers. they're very cute and critically endangered. furry cats that swim like otters. tonight we journey to the other side of the world and find the surprising reasons why their very existence may be in your hands. plus gaga.

it top the charts and then was everywhere from green on american idol, to a youtube cover with 95 million hits. what made this song go so incredibly viral. >> announcer: from the global resources of abc news with terry moran, cynthia mcfadden and bill weir in new york city this is "nightline," april 24, 2012. good evening. i'm cynthia mcfadden. tonight an investigation that blows the lid off a steamy world where girls are bought and sold for sex online. police all over the country tell us the sale of sex has dramatically increased with the advent of internet classified ads. two years ago a public outcry led craigslist to shut down its sex ads but much of their business went to another web site site, backpage.com owned by village voice media.

would shutting down backpage help stop the trafficking of underage girls? or are they as they claim, part of the solution? "nightline" investigates. >> reporter: it's a battle that's been waged on street corners since there were street corners -- sex for sale. but cops say the red light district is old-school. the new market is online for sex. >> you can buy it on backpage. you want a tennis racquet, you go to backpage. you want to go buy a teenage girl, about 13, you go to back page in the don't section. >> reporter: we'll call herges jessica. takes courage to do what she's doing, come out of the shadows and talk about a very dirty business. >> she obviously has a pimp. look at the ads she has. at 17, she was sold by her pimp on backpage.com.

>> you can clearly see she's in high school. >> reporter: a classified site where you can buy a toaster or a cd or a girl. >> every pimp has rules that each girl must follow. >> reporter: for those who think it's a victimless crime, listen. >> there was a time when i didn't obey the rules. my pimp decided to take a potato peeler. he came, grabbed me by my throat, threw me against the wall, took the potato peeler and carved it into my face and then ate the skin. >> reporter: that man is now in jail thanks in part to her testimony against him. her mission now is to make sure it doesn't happen to other girls. >> i was looking at your ad off of packback page. >> reporter: buying a girl online is just about as easy as ordering a pizza. >> i saw your ad on backpage. are you available? >> reporter: we spent a day with

a human trafficking unit in california where they routinely prowl the sites to find underage girls. >> are you available today? what about 3:30? >> reporter: right on time. there she is, just 16 years old. sadly just one of many. >> come on! >> reporter: all these girls were once sold for sex, too. their playground has all the markings of childhood but none of the innocence. >> a girl likes to chalk, like we like to draw and stuff. >> reporter: it's just a reminder of how young you all are. we met 17-year-old megan here at street light usa, one of the few places in the country where girls like her can try to finish growing up. her pimp is not behind bars so we've agreed to change her voice and not show her face. >> my first night he took me to a hotel. >> reporter: megan went with him, she says because he promised to be her boyfriend. >> he's like, we're going to take some pictures of you.

>> provocative, sexy pictures? . >> uh-huh. >> what did he do with the pictures? >> he posted them on backpage. they put the pictures that i put on there and people started calling. >> reporter: then did you start posting them yourself? >> yes. i learned how to write the captions, i learned how to take the pictures. i learned how to pay for the ad. and everything, it turned out to be very, very simple. >> so as a 17-year-old girl with a month of experience, it was easy as pie to post on backpage. >> yes. >> and how many tricks would you have a night? >> i'd probably have like up to 20, once i posted my ad the phone didn't stop ringing. i was so exhausted. i didn't want to do it anymore. >> so you were bringing in a lot of money? >> yes, i was. >> $3,000 to $4,000 some nights? >> yes. >> how much of that were you keeping?

>> none of it. >> we are hear to demand an end to sex trafficking and we're not going away! >> reporter: backpage has been taking a very public bruising from a wide range of critics. 48 state attorneys general have signed a letter urging backpage to shut down all their so-called adult classifieds. >> they profit from men who sell women and girls and allow them to be raped for money. >> reporter: washington state's attorney general rob mckenna says what backpage is doing is immoral. >> this is not acceptable behavior for an american company. >> reporter: to defend itself, backpage invited our cameras inside its headquarters. >> this is the first time we've actually allowed anybody in here. >> reporter: their new lawyer liz mcdougall took us into a room where she says backpage employees are examining every ad trying to catch under age trafficking. tough, because while you're supposed to be 18 to post an ad, no i.d. is required.

how good do you feel the company is in finding people who are underage and being trafficked on backpage? >> i think the company currently is better than anyone else out there. we're doing more than anyone else right now. can we do more? yes, we can do more. >> reporter: one way they can do more, the site requires a credit card number to place an ad so police can find the bad guys. but the girls tell us pimps get around that by using gift cards bought with cash which are untraceable. >> this notion of gift cards being able to be used, that's something that i'm willing to explore more now. >> reporter: backpage does screen out about 400 suspicious ads a month and forwards them to the national center for missing and exploited children. the company argues that while they might be part of the problem, they can also be part of the solution. and police departments around the country told us they do use the site to track down victims. >> is the system perfect? it's not perfect. and that's why i'm here to make

improvements. >> reporter: but can a company that reportedly makes tens of millions of dollars from sex ads really be trusted to patrol itself? i'm curious about how much money you make posting these ads. >> this is not about money, it's about fighting human trafficking online. >> it's been purported $22.8 million last year. is that correct? >> we are here to fight human trafficking online, and that is the reason backpage has invested more than 80% of its people in doing that. that is the reason that we cooperate with law enforcement to the degree that we do. >> right now my question is how much money does this company make posting these personal ads? >> and my answer to you is this is not about money. it's about providing a tool to save children online. >> so is $22.8 million last year accurate or inaccurate? >> this discussion is about stopping human trafficking online and the best ways to do that. >> why won't you answer the question?

>> because it's irrelevant. because this is not about making money. >> it's not irrelevant. >> it's shutting down the adult category on one web site was the answer sto stop child exploitation, i would be all over that and i would be saying, that's the answer. that's not the answer. >> reporter: she says the business will be driven offshore where it's harder to regular. the attorneys general say they'll follow it whenever it goes. so you know more than 48 attorney generals? >> on this subject, i do. >> what if you're wrong? what if you are now working for a company that is, in fact, helping exploit these most vulnerable kids? >> i grappled with that, and i stayed up nights with that before i took this job. there's no doubt in my mind that this game of whac-a-mole and villainizing one service provider after another is not the right strategy. >> if we could save one child

that one child could have been me that was saved. >> jessica has a new life now. working with fair girls. >> you can clearly see she's not even fully developed. >> reporter: a group crusading to get bathpage shut down. next up for her, law school. >> if i go to law school, there will be a way for me to help victims who don't have a voice of their own. i can be their voice. >> indeed she can. a bipartisan group of u.s. senators is now urging advertisers to pull out of backpage.com and tomorrow two senators will introduce a resolution calling for the sex classifieds to be shut down. well up next -- they're not your average kitty. they have webbed feet and love to fish and they may soon be going from rare to extinct. >> announcer: abc news "nightline" brought to you by geico. f chicago. people here sure are friendly

my accent. so to make sure people get every word of the geico savings message i've been practicing how to talk like a true chicagoan. switching to geico could save you hundreds of dollars on car insurance... da bears. haha... you people sure do talk funny. geico®. fifteen minutes could save you fifteen percent or more on car insurance. [ stella ] here's me. and here's my depression. before i started taking abilify, i was taking an antidepressant alone. most days i could get out from under and carry on. but other days i still struggled with my depression. i was handling it... but sometimes it still dragged me down. i'd been feeling stuck for a long time. so i talked to my doctor and she added abilify to my antidepressant. she said it could help with my depression and that some people had symptom improvement as early as 1 to 2 weeks. i'm glad i talked to her. i wish i'd done it sooner. now i feel more in control of my depression. [ female announcer

] abilify is not for everyone. call your doctor if your depression worsens or you have unusual changes in behavior, or thoughts of suicide. antidepressants can increase these in children, teens and young adults. elderly dementia patients taking abilify have an increased risk of death or stroke. call your doctor if you have high fever, stiff muscles, and confusion to address a possible life-threatening condition. or if you have uncontrollable muscle movements, as these could become permanent. high blood sugar has been reported with abilify and medicines like it and in extreme cases can lead to coma or death. other risks include increased cholesterol, weight gain, decreases in white blood cells which can be serious dizziness on standing seizures, trouble swallowing, and impaired judgment or motor skills. depression was always hanging over me. then my doctor added abilify to my antidepressant. now i feel better. [ female announcer ] if you're still struggling with depression talk to your doctor to see if the option of adding abilify is right for you. and be sure to ask about the free trial offer.

n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n

n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n >> announcer: "nightline" continues from new york city with cynthia mcfadden. they're fuzzy, nocturnal and growing more endangered every day. they're called fishing cats. they live in southeast asia, and it may surprise you to discover that the choices we all make could be affecting whether they survive. here's abc's dan harris. >> reporter: if you own a cat, you know they avoid water like the plague. but look at these little guys, diving right in. they are literally built for hunting in the water, with partially webbed feet and a head designed for diving. they're called fishing cats. there are very few of them left. they only live in southeast asia. and, as it turns out, their

entire future could according to conservationists depend on the decisions you make in of all places, your local supermarket. to find out why that is, we went to the other side of the world to remote, rural thailand. our guide, this young scientist named nam fong cutter, who has researched these fiercely private animals for eight years and has only once seen one of them in the wild. and that's good enough for you? >> yeah. in a way, that makes it even more exciting because you want to give them some respect. >> reporter: as a matter of fact, the only way we could take pictures of fishing cats for this story was in a zoo or in this wildlife rescue center where these cats hissed at us. that is a classically unhappy look. and each other. to show us the one way she can reliably see fishing cats, she took us out to their natural

habitat, which, to say the least, can be risky. >> there are a lot of snakes cobras. >> a lot of cobras here? >> uh-huh. >> terrific. >> reporter: when she and her team find some tracks, they set up a camera. >> so you set up a trap and then you put up a little bit of chicken. >> yes. >> that's cheating. >> it is. >> reporter: but when night falls, bingo. a fishing cat in the wild, an incredibly rare sight. critics say what we're doing here is putting these cats in danger. it has to do with what we buy in the frozen section of our supermarket -- shrimp. roughly 20 years ago, this was pristine wetland, now it's overrun by the shrimp farms, and they make that noise night and day. shrimp farmers dig these big holes and grow hundreds of thousands of shrimp, which are

then sorted, put on ice, and sent out. where will most of the shrimp go? >> a lot of this will go to the market in the u.s. >> this shrimp that we're seeing on the side of the road in thailand will end up in a supermarket in iowa. >> yes. >> reporter: iowa, california, new york, all over america. by one estimate, the average american eats upwards of a pound of thai shrimp a year. and if during your next trip to the supermarket you see the "from thailand" label, lovers of the fishing cat says there's something you should do. maybe put it back? >> yes, that will help. >> reporter: put it back she says, because these farms are actually threatening the cats in two ways. with their habitat being gobbled up by the shrimp farms, the cats are sometimes driven to kill chickens belonging to local villagers. then those villagers turn around and kill the cats. sometimes animals that she has been tracking for months simply vanish.

what's it like for you when you lose a cat? >> it's very, very sad because i'm attached to them. when you lose one, it's very sad. >> reporter: sad and all too common. and the solution, she says, may rest right here in america. for "nightline," this is dan harris in thailand. [ kyle ] my bad. [ roger ] tell me you have good insurance. yup, i've got... [ dennis ] ...allstate. really? i was afraid you'd have some cut-rate policy. [ kyle ] nope, i've got... [ dennis ] ...the allstate value plan. it's their most affordable car insurance -- and you still get an allstate agent.

i too have... [ dennis ] ...allstate. [ roger ] same agent and everything. [ kyle ] it's like we're connected. no we're not. yeah, we are. no...we're not. ♪ ♪ the allstate value plan. dollar for dollar, nobody protects you like allstate. i'm doing my own sleep study. advil pm® or tylenol pm.® the advil pm® guy is spending less time lying awake with annoying aches and pains and more time asleep. advil pm®. the difference is a better night's sleep.

don't you just hate it when you can't get a song out of your head? well, right now for millions of americans, that song is gotye's "somebody that i used to know." abc's david wright discovered, from the kids on "glee" to the wannabes on youtube, everybody seems to want a piece. ♪

>> reporter: in the era of youtube, the one-hit wonder can easily have nine lives. take gotye's catchy new single, "somebody that i used to know," 177 million hits and counting. now his whispered lament is one of the hottest songs in the country, number one on the billboard hot 100, covered on "american idol," covered again on "glee." but also covered on youtube by bands you've never heard of. ♪ you didn't have to do it ♪ >> reporter: this a cappella group has 3 million hits for its version. and there's this one, 95 million hits as the five members of walk off the earth all play one guitar. the cover has even inspired a parody. ♪ now and then we like to play one guitar together ♪

>> reporter: think of it as musical form of piggyback. they're not covering the classic. they're covering what's hot right now. members of the group say it's helped them breakthrough. >> everybody's going to be looking for that song. so why not look for our cover? >> reporter: this duo scored a hit with their rendition of chris brown's "look at me now." it got them 63 million hits, plus a record deal. lip-synching is such an audity, his dance moves so funky, it eventually brought 50 cent to his bedroom for a duet, 45 million hits. not bad. diymtv, sometimes it can be hard to judge who does it best. ♪ i'm david wright for "nightline" in los angeles. >> thanks, david. stop the music.