This is very scary. It sounds like one could be challenged to prove ownership to TSA/LE's satisfaction of anything one carries through the checkpoint - or face missing a flight and confiscation of that property.

Couldn't the same rule apply to someone taking 10 Rolexes or two dozen pre-loaded cards through security?

I was behind a flight crew once, I think possibly KE folks. They had shopping bags with multiple laptops. The TSO stopped the belt, had them take all the laptops out of their bags, then grilled them about where they'd bought them, why they had so many, how much they'd paid for them, etc. Fortunately for them, she allowed them to pass without summoning LEs.