I have said elsewhere on this forum that spotters could be very useful as a kind of "outer perimeter" security force. They are there to enjoy watching airliners, and nothing more. Anything suspicious would be reported immediately, since it is in the spotter's interest to maintain good relations with airport security and the police.
I sincerely hope that this will not affect my attempts to film airliners at various British airports (particularly Manchester), as I would very much like to make some money from selling airport DVDs in the near future.