'If you were in a changing room in full naked glory, you wouldn't want people to take your photograph,' said Judith Tan, a spokeswoman for the Singapore-based hotel chain Raffles International.
Raffles hotels ban cameras in bathrooms and changing rooms, though no peeping toms have been caught, Tan said Friday.
Just how to catch the roving cameras remains 'a huge concern,' for Planet Fitness, which operates three Singapore health clubs, said spokeswoman Christina Teo. Camera-phones are banned in locker rooms but not in the gym areas, Teo said.
The phones, which cost about 1,000 Singapore dollars (US$ 559), allow users to take and send images through multimedia messaging service, or MMS. The phones can also be used to send images to computers through the Internet.
About three-quarters of Singapore's 4 million inhabitants are mobile phone subscribers, giving the city-state the largest number of mobile phone users per capita in the world.