Regarding searches, a family member was on an internal flight in the Soviet Union back in the day. On arrival at their hotel, they found that their suitcase (which I think they said was locked) was precisely as packed - except for one item which had moved from the bottom, to the top. In other words, "we are letting you know that it's been searched, but you wouldn't know otherwise".
Regarding theft, one of my party walked away from their carry-on bags at the departure gate in BCN for a couple of minutes, whilst we were all queueing up. Gone. I can only assume staff - i.e. cleaners, snack-stand workers.
Regarding cling-wrap - still there at T2 BCN.