Okay, I was given to understand that if a cop had a reasonable suspicion that a crime was in progress that an implied "probable cause warrant" was considered to be in effect. This would include obvious stuff like hearing gunshots from a house, but could extend to things like a person having a history of drug sales hanging out on a street corner in a neighborhood known to be a hangout for dealers.<quoted text>(...good stuff about probable cause snipped...)
If I understood that idea, the biggest problem with it is that it's a bit vague and some cops (not all!) like to push the envelope as far as they can take it.
That seems like it might be consistent with your (obviously superior) understanding of the subject, but I'm not sure.