You could argue about my dress sense, but to confiscate my boots is just nuts.
From Canada (Sault Ste Marie) to Minneapolis it wasn't a problem, but on the connecting flight to San Francisco it was.
And in a way that's the problem: these rules are quite selectively/randomly enforced and even if there is paragraph somewhere that allows them explicitly I never even thought of challenging the official handed over my boots and bought a pair of new shoes on arrival in San Francisco. (Try finding a pair of shoes that early in the morning...)
So you're probably right, even so I'm not stupid enough to start a fight with a TSA guy and end up in more trouble than it is worth and they probably abuse that when they can get away with it (foreigners).
Their rules include something like 'The final decision rests with the TSA officer' so good luck challenging that.
They settle cases for millions each year where TSA employees were caught stealing from passengers.