I too remember incidents from the 80's where goofy stuff happened at airport s but lets get real, folks. Very few things at airports and on airplanes is the same as it was 20 years ago.
I've implemented systems for airports and can tell you that there are very few areas not covered by WiFi, wayfinder scanners and video cameras. And very few areas where employees and contracters are not scanned entering and exiting baggage areas. I'm not saying it doesn't happen and I'm not saying there aren't small airports with minimum security but if you're flying thru a major airport your bags are tracked everywhere and airport staff are double teamed for safety.
Like Sheldon, I say get insurance and pack well. If you travel, don't take anything you can't replace. I've checked cameras, laptops, guitars and other items and never had a problem for over 30 years. And I work for airports and airlines. Those people that try to carry all their bags onto the airplane and stuff them into the overhead bins are the ones that make me grind my teeth.
What about those guys at the hotels that store your bags while you have breakfast before your flight? A lot of them look pretty suspicious to me. And I'm sure the hotels hiring policy is a lot less stringent than the airport or airline one.