Many of our members old enough to remember the Baader-Meinhof days of rage in Europe will recall similar security procedures which were then in effect. The security inspectors were polite but firm, and armed Army patrols of 3+ walked through the airport constantly.
I can recall being asked ahead of boarding each flight to remove my then huge laptop and CALCULATOR for German and UK airport security. I had to turn both on and off, and then remove the batteries. No knives or sharp items either in hand-held baggage.
The next phase was outside, just ahead of boarding the plane. Passengers were required to identify all personal bags BEFORE they were loaded on the plane, with armed police and dogs standing by. In the summer heat, rain, sleet, or snow.
The take-offs were memorable, being abrupt and severe angled. The B-M gruppe had taken a photo of a Lufthansa jet using a a RG-7 target sight, which was published worldwide. Flying to and from the Mid-East on business was equally security-tight on board most flights, but despite the inconvenience, safe on my monthly flights.
Today, looking back, I'm still not sure what was worse: The heightened security or the food served at Heathrow.