Canada is just doing its duty in vetting out suspects in illegal activties. There's no way you can avoid it. They don't specifically pick on you, it's just that sometimes you've bad luck when they do.

With the recent events surrounding the China Kingpin drug smuggler who is seeking asylum in Canada for fear of persecution if sent back to China, Canada has got to be more deligent in weeding out possible refugees, smugglers and the like. For all the years I have been in Canada, I have seen immigration at both Vancouver and Toronto try to put their hand in preventing honest people from coming to visit. Commonwealth citizens do not need visas except from a few countries in the world, and yet I have seen Canadian officials give exact date visa entries to people even from UK, New Zealand and Australia. (Hence, asians are not the only suspects).

I've a caucasian friend who was asked why he flies so often between London and Toronto and how he can afford it. He just says that he's rich and that usually shuts them up.

So maybe you should just do the same.