I feel fairly confident that police don't usually attack media, but it seems clear that in the past few days there has been some kind of deliberate choice made to start doing so.
Are individual groups of police making the decision to attack media, or is it concerted? Are they just seeing it from other police and copying? I know some people will say it's because Trump has called media "fake news" and such, but is that really all it takes for police to start such gross behaviour? At the same time, I presume there hasn't been a direct order to start targeting media or it would have been leaked.