Case overview
Between 2018 and 2020, operators of encrypted chat rooms on Telegram coerced dozens of women and minors into producing sexually exploitative material through blackmail, threats, and impersonation. The network, known as the Nth Room case, involved multiple administrators who sold access to the material and controlled victims through systematic intimidation. South Korean authorities arrested the primary operators in 2020 after a months-long investigation that began with tip-offs from journalists and cyber activists.
How the network operated
The Nth Room network consisted of multiple private chat rooms hosted on Telegram, a messaging platform known for its encryption features. Operators recruited victims by posing as police officers, employers, or investigators, then used fabricated threats and personal information to force compliance. Once victims sent initial images, operators demanded increasingly explicit material under threat of distribution to family members, employers, or public forums.
The rooms were numbered and tiered by subscription cost. Access was sold to paying members who could view the material and make requests. Operators maintained control through direct threats, false legal claims, and manipulation of victims’ social networks. Many victims were minors, some as young as 11 years old, according to prosecution records filed in Seoul Central District Court.
Cho Ju-bin, who used the online alias “Baksa” or “Doctor,” ran some of the most heavily trafficked rooms. His operation alone involved at least 74 identified victims. Cho recruited accomplices to manage the rooms, verify new members, and execute the coercion process. He operated from late 2018 through early 2020.
What triggered the investigation
In July 2019, two college students operating under the pseudonym “Flame” began tracking the rooms after encountering references to them on public forums. They posed as users, documented the structure, and compiled evidence of criminal activity. The students contacted South Korean news outlets and provided detailed records of what they had observed.
Journalist coverage in late 2019 prompted public attention, but the investigation accelerated in early 2020 after additional reporting by major outlets including SBS and JTBC. The coverage detailed the scope of the network, the number of paying subscribers, and the ages of victims. Public pressure intensified rapidly. Within weeks, over 2.5 million people signed a petition calling for the identities of those involved to be publicly disclosed.
The Seoul Metropolitan Police Agency established a dedicated task force in February 2020. Investigators used digital forensics to trace Telegram accounts, cryptocurrency transactions, and device metadata. Cho Ju-bin was arrested on March 16, 2020, during a coordinated operation that also targeted other operators and room administrators.
The arrests and charges
Cho Ju-bin was charged with violating South Korea’s Act on the Punishment of Sexual Crimes, production and distribution of child sexual exploitation material, coercion, and blackmail. Prosecutors presented evidence that included victim testimony, chat logs, transaction records, and device seizures. Cho’s operation generated revenue through cryptocurrency payments, though exact figures were disputed during trial proceedings.
Authorities identified and arrested several other operators, including a man known by the username “GodGod,” who ran earlier iterations of the chat rooms before Cho. In total, investigators detained more than 120 individuals connected to the network, including operators, distributors, and paying members.
Cho’s trial began in May 2020. He appeared in court with his face exposed after a judge approved a request to reveal his identity, a rare step in South Korean criminal proceedings. During the trial, prosecutors detailed the methods used to coerce victims and the structure of the operation. Cho admitted to some charges but contested others, particularly regarding the scope of his direct involvement with minors.
On November 26, 2020, the Seoul Central District Court sentenced Cho Ju-bin to 40 years in prison. The court also mandated 15 years of electronic monitoring following his release and required him to complete 80 hours of a sexual violence treatment program. The ruling cited the calculated nature of the crimes, the number of victims, and the use of technology to evade detection.
Other convictions and ongoing proceedings
Several other operators received sentences ranging from 10 to 34 years. Moon Hyung-wook, another administrator involved in earlier iterations of the rooms, was sentenced to 34 years in prison in February 2021. Additional members who participated in coercion, distribution, or payment processing also faced charges, with outcomes varying based on the extent of their involvement.
South Korean courts handled hundreds of related cases through 2021 and 2022. Some members were charged only with possession or access, while others faced counts related to distribution, financial facilitation, or direct communication with operators. The breadth of the network meant that prosecutions extended beyond the core group into a larger subscriber base.
Legislative and policy responses
The case prompted immediate legislative action. In May 2020, South Korea’s National Assembly passed the “Nth Room Prevention Act,” which increased penalties for the production and distribution of sexually exploitative material and expanded the definition of digital sex crimes. The law also strengthened provisions for victim protection and mandated cooperation between platform operators and law enforcement during investigations.
The government launched reforms targeting digital platforms. Officials pressed Telegram to improve cooperation with South Korean authorities and to implement stronger content moderation policies. Telegram’s encryption model had made initial identification of the rooms difficult, and its operational structure limited direct oversight by South Korean regulators.
Victim support services were expanded through the Ministry of Gender Equality and Family. The government established dedicated counseling programs, legal aid services, and digital forensics assistance for individuals involved in the case. Advocates pushed for continued funding and institutional reforms to address gaps in digital crime prevention.
Ongoing debates and unresolved issues
Despite the convictions, questions remain about the full scope of the network. Investigators documented tens of thousands of paying members across the various rooms, but only a fraction were identified or charged. Many used privacy tools, cryptocurrency, and disposable devices to avoid detection. Law enforcement agencies have acknowledged the difficulty in tracing every participant, particularly those who accessed the material but did not engage in direct communication with operators.
The case also highlighted enforcement challenges related to encrypted platforms. While South Korea’s laws were strengthened, the technical infrastructure that enabled the network remains in wide use. Debates continue over the balance between user privacy and the need for investigative access to encrypted communications.
Victim advocacy groups have criticized the pace of legal proceedings and the resources allocated to ongoing victim support. Some victims have spoken publicly about continued harassment and the psychological toll of the trial process. Others remain unnamed and have not participated in public proceedings due to fear of identification or retaliation.
Where to look next
- Documentary: “Cyber Hell: Exposing an Internet Horror” (Netflix)
- Book: “Tracking Down the Nth Room” by Chasing Flame Team
- Podcast: “The Nth Room” (“The Dark Side of South Korea”, BBC World Service)
