"That means you can do.......nothing in Canada. Are you allowed to breath?"
Breathing if fine and free - especially the good clear air we have locally. I have no idea what smog is. :-)
No, I think the educators and such have gone off the deep end in some situations - no tolerance rules and such. Even in post-secondary schools they keep an eye on things like knives. As an adult in my workplace, it's a different story. Nobody has a serious problem with me carrying a pocket knife and multi-tool or two. The cops tell me there isn't even a 3" length rule for knives - just no automatics, switchblades, etc. Weapons are banned so unless you brandish your knife as a weapon, it's no big deal. Treat things responsibly and you are treated responsibly.
BTW, cell-phones are also a no-no in schools. Teachers get really pissed when some kid has their phone ringing in the classroom so I thing most schools "suggest" that the kids keep them turned off or at the most on vibrate while in class. Students who don't obey the rules can have their phones temporarily confiscated. A lot of people see the idea of kids with cell-phones as even frivolous or extravagent but then again I live in an economically repressed region.