Street brawls, slow sets

Someone told me about hearing of an arrangement by a group of clubs in some city to end the night's dancing with two or three slow sets.

According to the person who told me, there had been a lot of street fighting when the clubs were sending people out pumped up on fast music, but when the slow sets were instituted at the end of the night, the street brawls stopped in the clubs' area.

Does anyone know where this might have been? I've been trying to track it down for a few weeks. I thought the person who told me said it was in England, but someone else has now said no, it was in Cork.

I'm reposting this here since no one in the South forum replied. I hope someone on the more general forums will remember.