I think that the reason that police abuse seems to be a bigger issue these days compared to previous times is because there are more cameras, especially on mobile phones. I think that there isn't more police abuse. It is just a case of there being more cameras and technology.
The use of technology nowadays has been beneficial to many court cases in which police abuse or brutality is in question. No doubt does having a photographic representation of the events that may have taken course during an investigation or routine stop help to either solidify an officers defense or a prosecutors defense against an office and voce versatile.
Yes, police abuse and misconduct are likely becoming a bigger issue these days due to the proliferation of cameras. It is more likely that the abuse has been occurring all along, and is now simply being caught on camera, since it seems like everyone has a camera in their pocket these days.
Yes, police abuse has become a bigger issue because of the ubiquitous nature of video cameras on mobile devices, because we are now being able to see just how widespread the problem is. Police are far more likely to be thugs than we ever knew. Cameras are making them more honest. It is a scary problem.
Police abuse has always been an issue, and, honestly, there's a better chance than not that it has gone down in recent years than it has increased. People are talking about it more largely because it is more visible, and because it has become a hot button issue related to civil rights.