The very fact that they have to be used suggest the demonstrators are less than peaceful or failing to follow the lawful orders of the police and city officials involved. An example would be curfews once told they either should obey the orders or suffer the consequences. If they feel the law is unlawful fight it in courts or demand a vote to remove said law/ rule or even the elected officials responceable. Also turning a blind eye to the looters/ arsonists makes them no better than them.