More tangentially, as I usually fly outside the US, it's fair to say that this is far from just an American reality. For example, the Dublin Airport even explicitly mentions that hold baggage may also be searched by hand on their website: > "Both your carry-on luggage and check-in baggage will be checked by means of detection equipment and may also be subject to a hand search." [1]
I have a hard time believing that airports with any restrictions on what check-in/hold baggage may contain (virtually all of them, if not all) don't have any provisions for searching bags, although maybe I'm wrong here.
Although, what country doesn’t have the ability to dig through your luggage? In my personal experience, Europe is the only place that I’ve seen armed officers dig through 100% of the bags on a flight while the entire airport watched.