In an interview with H. Allen Smith, recounted in his book Low Man On A Totem Pole, ©1941, Sally Rand said she invented the Fan Dance as a way to skirt obscenity laws. Nudity was allowed on stage as long as the person was motionless, but nude dancing was prohibited. Her plan was to conceal herself as she danced, then periodically strike a pose with the fans open- “vogueing” sixty years before Madonna.
For the most part the police weren’t concerned with the finer points of the law, so she was still arrested pretty regularly.
(In this clip she is wearing a swimsuit, so nobody should be scandalized.)