...'spose you already saw this...?
It's weird. The cops in my hometown used to just set up across the street from the main bars. There'd be one unit parked near each bar and the rest on patrol. They were catching DUIs like they were going out of style.
Naturally, some liberal group (probably the ACLU) came in and sued, claiming the cops were "unconstitutionally profiling" and the police were ordered by the courts to stop the practice at once.
Of course, drunk-driving fatalities soared after that. But that was the cops' fault "for not doing their jobs."