I have asked this here before and never got a definitive answer. I was told a few years ago that people in Canadian parks who were determined to be professionals, by virtue of the type of equipment they carried, had their gear impounded. It was based on some regulation requiring permits and the authorities simply used the type of equipment as a the metric for who was a professional and who was not. I'm not trying to spread any rumors, just trying to get an answer. I've had to buy a work permit entering Canada several times because the customs and emigration people determined I was displacing a Canadian worker.