Last summer a friend and I were walking up Yonge St from Queen and a cop was minding a barricade due to street closures (Pride events were going on). There were two black guys ahead of us, dressed "street" style. The Don't Walk light came on at one of the intersections and they decided to cross anyway, as there was no traffic coming off the side street, or anywhere within sight.
The cop yelled, "HEY!", and not in a friendly way. He barked at them to stop and return to the other side. The guys kept walking. He immediately moved towards them and said "You got a problem?" while shoulder-bumping one of the guys. Hard. (My friend later said to me, "That's assault!")
The guys just kept walking, and I'm glad they did. If they had so much as talked back or became indignant at being yelled at and then bumped by this cop, all hell would have broken loose and there would have been a dozen cops swooping down to throw these guys to the ground (or worse).
If the persons crossing had been me or my friend, or perhaps more professionally dressed, the cop might have asked us to stop crossing and return to the other side, but he would have used a much friendlier (even if firm) tone. He snapped at these guys like he was yelling at his dog. Offered no respect. And when they ignored him, he had to take it up a notch to try and save face.
The guys were not supposed to cross the street. But it was a special circumstance as the road was barricaded to traffic and any reasonable person would feel safe to just continue on their way. The cop could have asked them politely, could have treated them with respect. But he chose to be a bullying ass, and it was easy to see how situations like this could easily spiral out of control and end up with someone getting hurt, all over something so trivial.
With the advent of phone cameras, many whites are finally realizing what blacks have known all along, that certain cops are overstepping and treating them differently, sometimes fatally so. I've heard many stories similar to the one above. I expect to hear more, despite the regime change.