Comment: back in 1994 I had to take a bus from texas back to british Columbia and there was a Mexican on this bus .
 He travelled all the way to the Canadian border and I noticed no luggage , no nothing except the clothes he was wearing which was a long leather black coat all the way down to his ankles.
myself I had 2 travel bags with my work clothes and so on,.
we both walked into the customs crossing  and he was right in front of me .
they asked him if he had identification and he said something  and they told him proceed and I never seen him again.
now I was next 
I am a Canadian citizen and I was asked for proof so I showed my drivers licence etc etc. and my work permit from the usa etc.
asked where I cam from and I said down in  Texas , my suit cases searched and I was told to go into a room , waited 3 hours before being asked many questions, I satisfied them I guess I was okay to legally enter.
but i always thought it was strange that people can just walk right into Canada .