Had to look it up:

http://en.wikipedia.org/wiki/UKUSA_Community

"The United Kingdom – United States of America Agreement is a multilateral agreement for cooperation in signals intelligence between the United Kingdom, the United States, Canada, Australia, and New Zealand. The alliance of intelligence operations is also known as Five Eyes (FVEY). It was first signed in March 1946 by the United Kingdom and the United States and later extended to encompass the three Commonwealth realms of Canada, Australia and New Zealand. "

I am aware, and that's something I've voiced my concerns about with my MP, but I don't see anything changing under our current government.

But even if we weren't, it would be possible for American agencies to intercept Canadian traffic without any sort of due procedure.