AVMan
To be fair, while there are differences, would the public know? Possibly not, have a look at some of the bigger Canon Lenses in the 600mm bracket.
Yes, an ex mil person would probably know, so would a photographer who was into very large lenes, but avarage punter? Doubt it.
From what I recall being near the fence with a SAM isn't a problem, it wouldn't have time to fuse before it hit, if it could hit at that range, it's someone in one of the parks a couple of miles out thats the worry on that one.
El G
Yes, and while they are looking inside the world could end around them, they'd not notice, as experience shows.
DFC, correct attack 1 did come from the car park of a hotel, nothing was noticed, because the drove into the car park, parked and left a few minutes before it went off. All parties are currently doing time for it. The spotter community would not have been of any use there anyway, as its not a place the airport can be seen properly, a pub and police Station being in the way.
As for the Irish history lesson, it's not quite accurate.