Thanks for the link to the earlier thread, Jochen, which I'd missed.
Similar thoughts occurred to me after my post in this thread to what some have written in the other thread. It seems strange that parents in the USA should criticise the "oppression" and latent violence of the airport security set with its armed police when every uniformed policeman you see in the USA is armed, as well as uniformed private security guards and, presumably, armed plains clothes police and private security guards. In addition, what I assume are the more extreme gun lobby supporters seem to want every American citizen to carry at least an Ouzi (not sure that's spelt right) submachine pistol with maybe an AK47 in the trunk of the car just in case. From a personal European perspective, I have no problem when in mainland Europe or the USA in seeing armed police on the streets, but I do find it disconcerting when in the UK, e.g. at airports. In fact, one day in town when I passed two armed police in the supermarket car park loaded down with shopping, I wrote to the chief constable about it. I quickly got a very apologetic phone call from a senior officer explaining that there had been a siege incident overnight in the town and that the officers concerned had been returning to the police station after this had ended for a debrief and had stopped quickly to shop for items for breakfast after the debrief meeting, but he felt they should have left their guns securely locked in their vehicle and had circulated an instruction that armed response officers should not walk around town armed when not directly involved in an incident.