Wow, on the surface that sounds really stupid, like the result of an incredibly socialist government and/or union influence on the government. Why would one make a smoke or any other fire detector difficult to get? Hopefully you don't live in such a place and know this from personal experience.
They certainly are subject to some sorts of regulation, considering an estimated 80% of the ones in home contain radioactive material. I think the context of the original post is somewhat different than what you're thinking. They're not regulated such that they are hard to buy (hardly, I can get one at any home depot in 5 minutes or less), but that they must be made to stringent standards if being sold to the public.
!c