The Homeland Security officer who had spoken to a spotter had stated: “There is no problem with spotting at US airports. We (homeland security) understand tail spotting, but before you start spotting please contact the airport police and let then know where you are and what you are doing. You will probably get a visit at some time from the local police, but it is all good natured”.

So, a couple of minutes’ effort will save us and local authorities from any misunderstandings.

(Thanks to Kev Sanders for his post.)