This week, the BBC showed scammers at work in an Indian call centre, recorded by an activist who hacked into the company's security cameras. Staff were seen laughing at their victims in the US and the UK. But who are these scammers, and how do they justify their actions?
Behind a pair of mirrored sunglasses, Piyush is telling me how he made a quarter of a million dollars.
"It was easy money," he says, detailing how he bought fancy cars and wore designer clothes.
From a modest background, Piyush made a fortune by defrauding innocent victims at the other end of a phone.
"To become a rock star we have to do something," he says.
"Become a thief?" I ask.
"Right," he replies coolly.
Piyush meets me in a friend's apartment, in one of Delhi's richest neighbourhoods. The group of young men I've come to talk to all have one thing in common - they've worked in India's scam call-centre industry.
The country is well-known for outsourcing jobs from Western countries to legitimate call centres, but there's also a thriving dark side.
For nine years after leaving college, Piyush was part of it. "I wasn't getting a job anywhere else and the money and the incentives were good," he says.
The company Piyush worked for ran what is known as a "tech support scam". It would send a pop-up to people's screens, telling them their computer had been infected by a "pornographic virus" or other malware, and giving them a helpline number to call.
As panicking customers rang in, Piyush and his colleagues would milk them for money, to fix a problem that didn't actually exist.
Piyush tells me that tricking people is an "art".
"We used to target the old people," he says.
"There are many old people in the US who don't have families, are alone and are disabled, so it's very easy to trick them."
I look at this man sitting opposite me in his baggy jeans and hipster T-shirt and wonder how he could be so cold-hearted. How would he feel if his own grandparents were victims of scamming, I ask?
"Yeah, I will feel bad," he says. "I did it because I needed money and that's it."
Piyush tells me how once he forced a woman to hand over her last $100, just so he could meet a target. For her, on the other side of the world, it was Christmas. "I took that $100 and she cried a lot while making the payment. Yeah, this was the worst call I ever had," he says.
Spying on the scammers
Campaigner Jim Browning hacked into a Delhi call centre run by Amit Chauhan and recorded this video:
Readers in the UK can click here to watch Rajini Vaidyanathan's Panorama documentary
The call centre featured in the programme was raided by a police a few days later - Amit Chauhan, is now in custody
Piyush went on to set up his own call centre. He tells me it was easy. He rented office space and told the landlord he was starting a marketing firm. His staff worked late hours due to the time difference with the US, so there were few other people around to ask questions about what they were up to.
As the boss, Piyush was constantly thinking of new ways to con customers out of cash. He drew up a script for another fraudulent scheme, known as the IRS scam, which involved cold-calling people in the US and telling them they'd get a tax refund of thousands if they first handed over $184.
"We used to tell them that the police will go to their house and arrest them if they didn't pay!" he says.
When he started out, Piyush was paid one rupee for every dollar he made in sales. So for a $100 dollar scam, he'd only get $1.25 (£1).
But once he became the boss the money flooded in. Some "lucky months" he took home $50,000 (£40,000).
Another ex-scammer, Sam, got into the business unintentionally.
Unemployment in India is now higher than it has been for decades, so when Sam was looking for his first job he thanked a friend for telling him about a place he could earn good money without working too hard.
At the interview he was told it was a sales job, pitching products to customers in the USA.
It was only while he was being trained in how to talk to customers that he realised what he was getting into.
"After a month, when we actually made it to the floor, when we were supposed to go live, that's when we figured out the entire thing was a scam," he tells me.
By that point Sam felt it was too late to back out.
"I was making more money than an MBA graduate and I don't have a college degree," he remembers.
"I used to drink a lot, party a lot, what are you going to do with all that money when you literally you don't have any future plans?"
Like some other scammers I've talked to, Sam wrestled with his conscience but told himself he was only targeting the wealthy.
"I just had to be sure that the customers weren't handing me the money for their food… so I always used to pitch to the big guys who can afford it," he says.
He could work someone's income out, he says, from "the way they talk, the sort of things they have on their computer".
"Is it OK to steal from people if you think they can afford it," I ask?
"Yeah," he replies confidently.
Sam says he's still in touch with some of the people he decided were too poor to be scammed, including a mother of three who worked in a fast food restaurant in the US.
He now helps her with any computer issues she might have, and is on her Christmas card list.
Sam says his high salary won him respect from his father, whom he no longer had to rely on for cash.
As we talk, he leans over and shows me the watch on his wrist, worth about $400. It was a gift from his boss for meeting his targets.
But his father - and friends - didn't know how he had come into such wealth. "When they asked what I did, I told them I worked for an IT company as a salesman," he says.
Six months into the job, the call centre Sam worked at was raided by the police and was forced to shut down. Sam escaped arrest and within days secured employment in another similar business.
His bosses were detained for less than a day and he believes they just restarted the business under a different name. It's easy for such companies to operate under the radar, he tells me, which is why they continue to do so.
Sam now has a job with a reputable tech company and has long left the world of scamming. He says he decided to talk to me openly to appeal to others like him to pursue legal jobs, which offer better prospects in the long term - and where you don't run the risk of arrest.
Unlike Sam, Piyush didn't hide his job from his family.
"I told them everything. They knew I was earning a lot and were pleased," he says.
As I glance down at his jeans, I can see a patch stitched on, with the words "take every chance".
But after close to a decade of scamming he too quit, in fear of police crackdowns. He feels lucky he never got caught, and now regrets his actions.
"I felt good at the time," he says. "In hindsight it doesn't feel as good."
Piyush used his earnings to set up other legal businesses - but ended up losing it all.
"After that it didn't go right," he says.
"So, I would say it was karma."
Piyush and Sam are pseudonyms