Police should be given clear permission to use water cannons against rioters and rules about when it is appropriate. Police see water cannons as an effective means of dispersal in some scenarios, incurring fewer injuries to the public than either uncontrolled rioting or other methods of control. In dealing with street riots in major cities last year, police wasted valuable time waiting for overall direction from politicians who fear that inappropriate use of water cannons might antagonise the general public. Clear guidelines could be agreed about using water cannons, for example to deal with rioters who throw missiles and petrol bombs and also where fire and ambulance crews are under threat.