I retired from the police some years ago and I could weep as I see the last links disappear between police and public. The old values of policing by consent, patience, common sense, discretion, co-operation have been replaced by confrontation, use or threat of arrest and force as a first resort, justified by "the circumstances as I saw them at the time, sir". The writing has been on the wall for some years now but the recent national security and terrorism concerns have rapidly accelerated the process.
Some years ago (during the 90s) there was a need for police officers to receive training, not only in the use of force but also in justifying such use. This was born out of a number of complaints and court actions about the use of force which was totally legitimate but the officer(s) concerned were inadequately prepared to answer for because they had not given sufficient thought to explaining their justifiable action later. They had acted instinctively from experience rather than thinking about how lawyers would deal with their evidence. Some police officers found themselves hesitating and even being injured because they feared the consequences of using force. Thus self defence classes and public order training began to include instruction and advice on proportional use of force, on when force is justified, on "perceived threats or likelihood of violence" as well as actual threats and actual violence which neatly led on to how pre-emptive strikes (hitting first) could be justified in certain situations. Very laudable and useful to officers genuinely experiencing such situations but the downside is that less scrupulous or gung-ho officers now had a script to justify their unnecessary use of force.
Protective equipment has also improved and in real riot situations has saved officers from serious injury. Of course the presence of officers dressed like this needs to be justified, these days it is but not only by real threat but also by the catch all "perceived threat". As I said, counter terrorism has provided a huge umbrella of justification for what you experienced. Officers are now pretty well protected physically from injury by what they wear and pretty well protected from their actions (shouting commands and using force/threat of force as a first resort) by using a "script of justification" they've been given, rather than to actually think about what they were really dealing with and interacting properly with the person in front of them. When they appear and behave like this in situations which to most observers seems over the top and unnecessary the effect on the general, law abiding public is to drive a further wedge between them and us and public support of the police shrinks further.
Senior officers need to reconsider how they deploy public order squads and the training they are given. The emphasis needs to go back to obtaining co-operation by reason and good humour (which can be backed up by force if necessary)rather than screaming at and threatening everyone whether they are a real threat or not. Of course officers need physical protection and support for their actions when the circumstances genuinely demand it but the pendulum has swung too far the other way.
A 'rebel conservative':
After being confronted with a "skirmish line of black-clad, helmeted figures, each carrying a large round black shield and a big club. All were wearing clompy, macho boots" you should take some comfort in the fact that it could have been worse - you could have forgotten to pay your TV licence... Sadly, I say this only half in jest.
At the root of this problem is, I believe, our tragic descent, as a society, from one that treasures liberty, to one that revels in licence. Sadly, few people appreciate the distinction.
When social control breaks down, when order is not established by self-restrained individuals and communities, it will be imposed by the State. The response from authority is entirely predictable, it tries to impose order on society, with ruthless and officious brutality. At one time the State would have imposed Christian moral standards, but now, with Christianity "out-dated" they enforce the prevailing liberal orthodoxy. So, public sex is fine, but we now daren't mix plastics with glass recycling. Because the State deems itself the arbiter of moral conscience, it follows that dissent can not be tolerated in any meaningful way.
Interestingly, this is the reason that Locke maintained that in a free society, private citizens must retain religion as a form of social control. As a society, we have abandoned religion, it plays no role in the lives of most people. Religion, when it is discussed at all, is mocked and ridiculed as fairy stories or derided for "imposing their morals on others." Should we be surprised with the result?
A reminder why some of this is necessary:
The 'militia' look of the police? Well, the helmet came from brain-damaged colleagues. The overalls came from burned colleagues. The shields came from colleagues battered by bricks. The no-nonsense tone came from colleagues who allowed themselves to be berated into letting someone go down that road, and from the shame when that person came to harm because it wouldn't have happened if they had stuck to their guns.