I address this below. Adding my personal interpretation onto it, I think it's fear-mongering and the only enforcement and successful litigation I've seen on it

I address this below. Adding my personal interpretation onto it, I think it's fear-mongering and the only enforcement and successful litigation I've seen on it is when tax is actually not paid. If you're worried, seek legal council and pay your use tax. Consider also this Montana-route may require being brave because when you make a stand for something like privacy, which is under attack, you too may be attacked even if you are in the right legally.