Maybe it's been the media that's been spreading this myth?
It's more that people generally have no idea what the US laws actually ARE in regards to many things related to firearms. At the national level they are indeed legal but regulated and taxed. Some states have flat out bans... not many, but some do.
With Canada, your firearms laws tend to be stricter than those here.
A quick internet search indicates that Canada requires a permit to own one, but such permits are no longer being issued. If someone has such a permit it was not invalidated, but if you don't have one you likely can't get one. However, you will need to consult someone more knowledgable about the specifics of Canadian law in order to get the actual information.