well how come police are vilified for using violence when its okay for protesters to use violence
Things need to change.
As an African American, looting a 7-11 has absolutely nothing to do with the shooting, it's simply a lapse into anarchy, and a good example of what America (or any nation for that matter) would be with almost zero general police/authoritative presence.
On the other hand...
The way the Police in America treat their mishaps and mistakes is disgusting, issues like police using live firearms when they could have attempted to use tasers first, or beating people down who are already unconscious. Things like these are simply skewed and twisted by the Department in their official statements to the public, the officer gets a slap and the wrist or a trial in which he wins, and then he's simply back to doing what he was before.
Problems like how Police officers are trained and punished for abusing their powers are either not forceful enough or non existent.
It's basically "What came first, the chicken or the egg?" Who started the cycle? Doesn't matter. If the Police get more violent, protesters will naturally use violence in response and vise versa, what needs to happen is somebody or something needs to stop the cycle of escalation that we've been constantly going down.
Also:
https://twitter.com/ACFromDaBranch/status/592839101574946817
Poll