I don't understand the automatic British "No" to such suggestions. In fact the opposite would be advantageous in the rare event that something happened. Cameras are cheap, plentiful and small.
Hundreds of airports have them.....handy for the aircraft enthusiast......try Salzburg on a Saturday during snow season.....I fly to Dusseldorf quite often...I've even tracked other family members walking through the terminal....very handy.
[Absolutely not true.....just in case civil liberties geeks are monitoring]