Thanks also Wolfgang. I am concerned also about many of the potential targets you mention. Many years ago (probably 20 now) while I was working as a technical writer and doing some work concerning the nuclear industry, I was allowed to walk unchallenged via the back entrance into the supposedly high-security Sellafield (then Windscale) plant in Cumbria, UK where the guards are armed (I hasten to add I did have official clearance to be there, but there was no check).

I did take the trouble to mention this on my way out via the main entrance and I sincerely hope security is better these days. I mention it only because this was in the "security-concious" UK at a time when there were many and various security alerts.

mooman