South Korean police have arrested four people and charged them with hacking into more than 120,000 internet-connected video cameras in homes and businesses, then using the footage to produce and sell sexually exploitative material online.

The National Police Agency announced Sunday that the suspects independently exploited security vulnerabilities in Internet Protocol cameras such as simple or default passwords to gain unauthorized access. The hacked footage was then distributed on an overseas website, the BBC reported.

IP cameras, often used for home security or monitoring children and pets, were compromised in a wide range of private and public spaces, including private homes, karaoke rooms, a pilates studio, and even a gynecologist’s clinic.

“IP camera hacking and illegal filming inflict immense suffering on victims and are therefore serious offences. We will eradicate them through vigorous investigations,” a cyber investigations chief at the National Police Agency, Park Woo-hyun, said in a statement.

According to police, the suspects were not accomplices, but operated separately. One individual is accused of hacking 63,000 cameras and creating 545 sexually exploitative videos, which he allegedly sold for $25,500 in virtual assets. Another suspect reportedly breached 70,000 cameras and sold 648 videos for $13,100. Together, these two were responsible for about 62 percent of all videos posted to the illegal site over the last year.

Authorities are now working with international agencies to shut down the website and investigate its operator. In addition to the four main suspects, three individuals who allegedly purchased and viewed the material have also been arrested.

Police have begun notifying victims at 58 locations, advising them to change their passwords and assisting with the removal of the illicit content online. Efforts are ongoing to identify more victims and the police have set up victims’ counseling support through the nation’s Digital Sex Crime Victim Support Center, according to Korean news site MBN.

In a statement, the National Police Agency stressed the importance of user vigilance. “Above all, it is crucial and effective for individual users who have installed IP cameras in homes or business premises to remain vigilant and immediately and regularly change their access passwords,” the agency wrote.