I think the thing is, in the UK we are use to very well regulated protest. The Public Order Act imposes liability and restrictions for notification of public rallies (over and above the specific restrictions in London). Coupled with good public order policing experience, deployment of tactical advisors to the police command structure and protest liaison officers to the protest organisers - the overt side of planned public order policing is pretty well sewn up. Obviously there are covert tactics which may or may not be employed; for which you can read any of the blogs alleging every other protestor is an undercover police officer (every protestor in Kent). Obviously spontaneous disorder is another matter; the likes of the disorder in Hackney for example cannot by it's nature be controlled. Quite how the local US police were supposed to cope with such a heavily armed militia turning up is beyond me. Watching some of the footage you can see local and state police uniforms; and now the federals have turned up for the post-bunfight investigation. With the amount of firearms about; it's quite impressive that so few are dead quite frankly. I would imagine the post-incident investigation is going to require a mass trawl of CCTV and so forth for the identification of offenders. It all relies however on whatever local, state and federal offences may have been committed.