"Thank you for putting a brake on the life of a devil that could not be stopped."
That is how one suspected ringleader of a clandestine online sextortion ring in South Korea described his relief at being caught.
Cho Ju-bin, known as "The Doc," operated chatrooms where he blackmailed dozens of young women, including at least 16 minors, into making sexually explicit videos of themselves.
They often featured rape and violence.
He then sold these videos online through Telegram, an encrypted messaging service. Fees ranged from $200 to $1,200.
But this was not the first - his "Doctor Room" was itself a copy of existing "Nth Rooms". Customers paid to access the so-called "Nth Rooms", where extorted content was uploaded, often in real time.
There are countless similar chatrooms, suggesting that there are tens of thousands of paying members.
According to Korean newspaper Kookmin Ilbo, each of the rooms hosted videos from three to four girls who had been blackmailed by chatroom operators.
The chatroom operators contacted the girls, promising modelling or escort jobs. They would then direct the women to a Telegram account to provide personal details, which were used to blackmail the victims.
Cho is facing 14 charges including rape, blackmail, coercion, and illegal production and distribution of sexual content. His trial began on 11 June, three months after he was arrested.
He has admitted that he produced sex videos and distributed them on Telegram, yet he is denying that he resorted to coercion, blackmailing and violence, according to his lawyer.
But while the focus is on the alleged perpetrator, his victims have a lonely struggle ahead.
In socially conservative Korea, the dozens of women and children who were exploited in the videos face a long and difficult journey to rebuild their lives.
One woman helping them is Lee Hyorin. She told the BBC about her work fighting digital sex crime.
Image captionLee Hyorin has spent the last three years taking down exploitative content online"There were times I felt that me taking a break is a sin; if I sleep it means more sexual abuse videos get out there and victims suffer more," said Hyorin.
"So initially I thought even if it means I work all night all day, I have to delete all these videos."
She has been dealing with the devastating consequences of digital sex crimes since 2017.
This initially involved working to take down content - but she soon realised that merely expunging the evidence of a crime was not sufficient.
"When sexual abuse videos first emerged as a social problem, there was no system to help the victims," she said.
"That's when our organisation, the Korea Cyber Sexual Violence Response Centre, launched. Our goal was not just to delete them, but to provide counselling to the victims from a women's rights perspective."
Hyorin quickly realised the value of her work in treating the lasting damage caused by these crimes.
"Many victims are horrified to see how their intimate self is being shared, being saved, now and ten years later, and used for entertainment or making money," she said.
Image copyrightJILLA DASTMALCHI/BBCMost victims who come to the centre start by setting out excuses.
"It really breaks my heart when they do that," Hyorin said. "I make sure to tell them at great lengths that 'you're not responsible for this and it's not your fault'."
She believes that being liberated from this guilt is the foundation of their recovery.
"It's sad but many victims actually don't have people around them who tell them what I tell them."
Instead, people blame them or judge them and this is why many victims feel so much guilt and shame, she said.
Image copyrightJILLA DASTMALCHI/BBCIt takes a good deal of courage to come forward. In fact, Hyorin believes the victims of the Telegram sex trafficking case who've come to her organisation represent only a very small percentage of all victims.
"Victims often go through such an arduous journey before coming to us - with police, media and so on. They come to us all hurt and exhausted."
Many victims give up along the way. She works with the victims to help them regain a sense of control over their lives.
"Our definition of recovery is when they are no longer just passive subjects who are consumed by the damage they've suffered, but when they digest the incident as one of many of life's experiences and go on to live their life."
Image captionCounsellors need counselling too, says HyorinBut Hyorin's work comes at a personal cost.
"I do feel their pain when I provide counselling. I suffered from something like post-traumatic stress disorder.
"In the Nth Rooms case, the men forced a girl to commit incest. It was so shocking how they are depriving the victims of their dignity and violating them," she said.
Exposure to this content has an effect on her personal life too.
"I also feel the fear myself. Before I joined this organisation, I ran into this illegal sex video whose thumbnail looked a little like me and my partner.
"I cried all night horrified at the possibility, and only at dawn did I download it and check that it wasn't me. Even when I delete sex videos for work, if I run into something that features someone who looks like my little sister or a friend, I check it. Just in case."
Time helps her come to terms with the worst aspects of her job.
"Two years ago, when I was asked to delete someone's content, I was traumatised by this thumbnail of a sex video. It stuck with me so strongly. But I'm okay now. So I guess as time passes, I get over the shock."
She, too, has sought help. "Counsellors get counselling too," she said. "We have to deal with lots of stress."
Image copyrightREUTERSImage captionCho Ju-bin outside the police station, wearing a neck braceDigital sex crimes are often very difficult to prosecute.
Those arrested for digital sex crimes have frequently been let off with a warning, and where prosecutions are successful, they often end with lenient sentencing.
According to Supreme Court data, of 7,446 people who stood trial for illicit filming between 2012 and 2017, only 647 (8.7%) received imprisonment or a fine.
This has greatly angered people in Korea.
"Over and over again women have told me they feel the justice system does not adequately punish sex crimes and does not act as a deterrent," said the BBC's Korea correspondent Laura Bicker.
"And over and over again tens of thousands of women have urged the current administration to act."
The government has vowed to revise the laws governing sex crimes including online grooming and the blackmail of children and teenagers.
Following a crackdown on digital sex crimes in May, the National Assembly revised laws making it illegal to watch, store, buy and possess non-consensually captured videos and photos, with punishments of up to three years in prison or a fine of up to 30 million won ($25,000).
Previously, watching or possessing illegally filmed images was not punishable.
In the Nth and Doctor Room cases, Korean police say that 664 suspects have so far been taken into custody, including most of the key suspects.
But some judges continue to treat digital sex crime perpetrators with leniency.
Women's rights activists held a protest outside the court where Cho is standing trial, saying that unless he receives a stricter sentence, there will be further exploitation cases, and ever more victims.
Image copyrightJILLA DASTMALCHI/BBCHyorin's motivation to continue in the fight against digital sex crime is clear to her.
"I lived 2018 in sheer rage (asking myself) 'Why does it have to be so unfair?' 'Why so insulting?' I was so mad that I couldn't stop working. I guess you could call it a 'calling'.
"We don't have a 'closed case' per se. That is our biggest predicament. We provide help to victims of revenge porn and digital sex crimes until they recover."
Each time they delete a video, they allow somebody to start their recovery process, she believes. But the routine of taking down illicit content and shutting down operations never really ends.
"Digital sex crime can strip someone of their basic human dignity - that's why we must never stop doing what we do."
Illustrations by Jilla Dastmalchi
By Hyung Eun Kim, Julie Yoon and Mark Shea