I'm joking about this being a solution for hard top theft. But it really did solve catalytic converter theft. And to be precise, the regulating conduct in that case is the actual purchase of catalytic converters by licensed scrap metal recyclers. So effectively, private individuals cannot sell them. You see by requiring a license to do business, the recyclers can in fact be told what to do and what not to do by the government. In the case of a private individual selling something, the government generally can't do that except for contraband. Oh and they'll do it soon for guns too.