There might be some truth to this, but I suspect a lot of this perception has more to do with the dramatic increase in recording equipment in the general public

There might be some truth to this, but I suspect a lot of this perception has more to do with the dramatic increase in recording equipment in the general public. Given how often police officers get away with pretty clear cut abuse even when there is video, it's not hard to imagine the majority of this behavior was getting swept under the rug.