Four men have been arrested in South Korea, accused of secretly filming 1,600 hotel room guests and selling the footage via a website.
Mini-cameras were installed in TVs, hair-dryer holders and sockets. The men allegedly earned $6,200.
If convicted, they face up to 10 years in prison and a 30m won ($26,571; £20,175) fine.
The covert filming of sex and nudity in South Korea has been described as an epidemic and has sparked protests.
Korean police said the men set up the 1mm lens cameras last August in 30 separate hotels across 10 South Korean cities.
In November, a website was then created, allowing users to pay for full videos or watch 30-second clips for free.
The men reportedly posted 803 videos and evaded the law by basing the website server overseas.
Police said the men earned money from 97 paying members before the site was taken down this month.
