The EDS machine that x-rays your checked baggage specifically highlights suspicious items. The screener only checks the items identified by the x-ray machine inside your checked baggage. This is different than the x-ray of your carry-on items which is based on a human interpretation of the x-ray image and requires a different search technique. When searching your carry-on item, a screener may conduct a complete physical check of your carry-on item or may search only the suspect area and then have the carry-on item x-rayed again.

There is a protocol for a complete physical inspection of your checked baggage, but it is done under specific circumstances.

As for zipper tags, well, all I can say is that they don't make 'em like they used to. Not trying to be flippant here; however, your luggage takes quite a beating just going down conveyor belts, shooting out of the EDS machine, being handled by both TSA screeners and airline baggage handlers, being loaded and unloaded from aircraft, thrown into trunks of cars and other normal wear and tear. The little wheels on the bottom of your bag are usually made of cheap plastic and they crack very easily. Often, people overstuff their luggage, which puts a lot of strain on the seams and results in tears along the stress points as well as the zipper tabs where people put a lot of force as they try to zip the bag closed.

Yes, there are screeners who mistreat your luggage. The same goes for airline baggage handlers, taxi cab drivers and skycaps. This is part of the entire equation, and I'm not trying to justify it. I'm just sharing my observation.