[trebleshot]

Actually it depends. If the charge is for shipping alone, then you're right - they cannot legally charge tax on shipping in the US. If, however, it's listed as "Shipping & Handling" or "Shipping & Processing", then they can and will charge tax on the whole fee. And most likely when you ask them why, they will say that the services are charged in a bundle and there is no way for them to separate it out.

Regardless, $5 in taxes for a $25 item seems just a tad steep no matter what state you're living in. That's 20% of the item cost! What was your S&H charge? Maybe that might explain the obnoxious tax rate.