Heathrow may be the largest and busiest airport in Britain, but for spotters and other members of the general public that want to watch/photograph/film airliners at a major airport, Manchester is second to none. It is a shining example of what actually happens when airport authorities work with aircraft enthusiasts, and not against them.
It stands to reason that spotters would report any suspicious activity immediately, simply because any security breaches could ultimately have a direct impact on them. I marvel that certain airport authorities don't recognise that obvious fact.