Got a link or what exat case are you talking about?
I took a class in college taught by a judge and he spoke alot about these situations.
I'm not up on recent cases but basically the police have to publicly post the area where they are doing it and the days and times. Police can't use dogs to search cars although that has been in recent cases as well. Police also have to decide how they will seach and stick to it. For example they must say we will search every third car., they then have to do this, tehy cant say I wanna search this car b/c its a young guy or black guy if he's not hte third car he has to not stop them without probably cause. IF they say every car they must search every car but this isnt practical as you would back up traffic too much.
