My state had line item on the tax form asking for the amount of goods purchased online so then they can tax them.

Always wondered what people put in there and if the state even did anything about it (audited people).

I guess they could ask Amazon for records (threatening a lawsuit) and cross-reference with all the reported taxes based on name and address. If user bought just from Amazon more than what they reported they they have obviously owe some money + fines & late fees.

(But I suppose I am making gross assumptions about the competence and general technical abilities of my state's tax collecting office).