The cops up here have enough to deal with. The legality of possession in Canada has been on and off for sometime now. The govt. is currently trying to set mandatory minimums for growing now, though it has a few more steps to take before that comes to fruition
In BC, I have been caught with a half ounce of weed or more, 4 times. No criminal charges stemming from those incidents either.
It's technically not legal for possession (though possessing up to an ounce was legal for a while, and it seems to flip back and forth and laws get repealed up here as often as Paris Hilton needs to wipe her chin)........
but the laws are generally relaxed....at least at this moment in BC. Alberta can be a little sticky. Don't now Ontario very well, but I would assume with the population and other issues in largely populated areas as such, the cops would have better things to deal with.
As long as you aren't out causing other problems, I have found MJ laws up here are there, but often overlooked, or dealt with mildly.