That's weird, I am also Canadian and my profile says that they can only proceed with my application with people who hold an US visa and/or work permit. I thought it was a mistake so I contacted their support team and got a reply saying that they can only consider my application if I live in the US.

Did you change your location to some city in the US?

How did you get your application accepted?

On the same note, Hired.com which seems to be a direct competitor, also has restrictions on the locations available for their recruitment process. In Canada, for example, they only accept people living in Toronto. Or people lying about their current location because they are planning to move there.