The valid reason is to get a massage in a massage shop...
And they can 'charge' you with a lot of stuff, but they have to prove it in court, and a judge/magistrate has to find you guilty.
If you are having a beer in a bar which is also being used to sell illegal drugs or firearms, for illegal gambling in the one of the backrooms or whatever, that doesn't mean that you are part-taking in criminal activity or had any intent to do so.