As several commentators have noted, other E-ZPass agencies have no fees and are more than willing to send transponders to out-of-state residents. So there will be nothing stopping someone from Minnesota from getting say a Massachusetts transponder and then using it here if Minnesota decides they're going to charge a fee to get a transponder locally. The main drawbacks to doing so are lack of local walk-in service, and most agencies there is no switch on the device itself to disable it for use in carpool mode- to avoid being charged a toll as a carpool you would have to remove the device from your windshield and either take it out of your car and put it in a shielded bag.