If it is fraud, then at what point is it not? If I used it for a day/week/month before bringing it, is it ok? Intent matters I suppose, but how do you prove intent to circumvent import duties, versus just bringing my stuff? I genuinely don't know, seems like a lot of gray area.
IANAL, but I think if you were legally resident in the USA for some number of years, and then moved to the EU, you could bring your personal possessions with you.
If you travel to the USA for a week and buy something, that's subject to import duty.