Flt Deck visits
As crew we do allow Flt deck visits, but also pending on the PIC. Some time we allow them during flt, and sometimes on ground.
Children love it, and we don't have problems with it, by the way that's how many of us pilots became in love with flying, it was that one time visit that got us hooked on aviation.
Today, you need security check, background check, MI5, MI6 checks, CIA, NSA, what ever agency that's out there and may be x-ray before we enter the flt deck and just to see how it looks.
Let's hope this changes again, we can enjoy jumpseat again if you are crew from different airlines to see how different things are and enjoy talking about aviation.