Cho Joo-bin (Korean: 조주빈, born 14 October 1995) is a South Korean who is involved in the Nth room case.
Born in 1995, Cho studied Information and Communications at Inha Technical College. He had completed the national service from 2016 to 2017. He also joined several voluntary services i.e. at an orphanage. Some sources also reported that he used to active on Naver KnowledgeiN.
Cho was reported as a hardworking student with 4.0 CGPA, as well as joining anti-violation campaigns at his university and police offices. 
Nth room case
During the early 2020, Nth room case has been viral on South Korean society. On 23 March 2020, SBS revealed the personal information of its suspect, who is Cho. The next day, police also confirmed his identity.
Cho was widely accused for sexual harassment, with some victims are reported as minors, including secondary students. He was also reported that he had ever threatened Sohn Suk-hee.
Someone with the nickname "God God" created the "1st room" up to the "8th room" (nicknamed "nth room"), and uploaded pornography of sexual exploitation. Someone with the nickname "watchman" uploaded that link and allowed it to be accessed in a Telegram room called "Gotham room". However nth room disappeared in September 2019, and other rooms appeared instead.
It is true that Nth room started first, but it is more bizarre, the magnitude of the damage and the number of victims is much larger, and the place where the crime was conducted is the Doctor's room. One fact is that 16 of the officially known victims were minors, including middle school students.along with the fact that there are 30,000 paid members who traded those videos.In Doctor's room, sexually exploitative pornography was distributed via a Telegram chatroom, and was only accessible by crypto-currency payment. "Doctor", who appeared in July 2019, threatened women, and took sadistic pictures and videos by figuring out their personal information, and then uploaded these pictures and videos. When reports first started, Doctor even figured out the personal information of the reporter, and circulated it. In addition, a high school student in Incheon was running various Telegram chatting rooms that distributed child pornography and links for buying drugs, and even shared tricks for dealing with police investigations.
On March 23, 2020, SBS first disclosed the identity of the "Doctor's room" suspect. His name is Cho Joo-bin. On March 24, following a decision of the Personal Information Disclosure Review Committee of the Seoul Metropolitan Police Agency, an official identity disclosure measure was taken, on the basis of Article 25 of the Act on Special Cases Concerning the Punishment of Sexual Crimes. The suspect is Cho Joo-bin, born in 1995; this is the first case where an official identity disclosure measure has been taken for a sexual criminal. It has been revealed that Cho Joo-bin graduated from a technical college in Incheon, and was a reporter for the university newspaper. It is also suspected that he was active as a ilbe member, although this has not been confirmed.