A lot of the headshops in minneapolis will throw you out of the store if you start making references to using them for pot. They got a business to run, and a few of them have audio monitors set up by the Minneapolis PD, they can get in serious trouble, even lose thier shop for discussing illegal matters with you. So do them a favor, we all know it's funny and no one uses a "water pipe" for tobacco ever, but just go with it if you want your headshop to stick around.