Should I lock my luggage for a flight from the US to Canada?

Personally, I would not bother. I have a TSA compliant lock, and have looked at quite a few in various stores, and,in my opinion, none of them - not a single one - is able to prevent anyone older than 6 from getting into a bag if they want to. They are all flimsy, the shackle is not actually held into the body of the lock by anything strong. I think that a screwdriver or a pair of pliers would be enough to just twist the lock apart.

I no longer bother to lock my checked baggage, on the few instances where I have any. I also make sure that I put nothing valuable or important in the suitcase.

If you want to get a small, real padlock to use when you are in a hotel, then that is a very reasonable thing to do.

I have traveled over 1,500,000 air miles. My most recent flight was on Sunday.

I have never locked my suitcase and I've never had anything go missing. I have had my bag opened because TSA has put notices inside.

I obviously wouldn't waste the money and since the locks can still be opened, what's the point?!?