UK being non-Schengen, passengers leaving on a UK bound flights are checked at check-in, then by the BGS, and finally by the gate-staff.
I believe I am right in saying that if you are travelling within Schengen states, then checks are limited to check-in, and possibly by the gate staff - though I cannot remember being checked last time a flew to AMS from Nürnberg.
What I always find slightly strange is that when you check-in in UK you get the "20 questions" regarding who packed your bags, if anyone have given you anything etc - but this never seems to happen at check-in elsewhere - though I understood that all passengers checking in for flight to UK were supposed to be interrogated at check-in.
I'm only SLF, and may be wrong. I'm sure I'll be corrected if am.