Airsoft is a sport for those 18 years of age or older; while there are minors who acquire airsoft guns and organize games themselves, they are usually in public spaces and not conducted in a manner that is responsible. As such, they usually run afoul of law enforcement officials sooner or later.
As Scarecrow said, it is advisable that your son wait until he has reached 18, and then he can become involved in the larger, more established community here in Canada.
Thank You for seeking guidance on this matter, if you have any other queries I'm sure others here would be happy to answer them.
Edit: Also a final note, I'm noticing some contradictory advice being given in this thread. Something you should note are the "Age Verified" tags that you'll see under user's names here. Users without them are underage players (or haven't bothered to get verified, not invested in the community) and surprise surprise, they will tell you "no problem, it's cool". Listening to them would be tantamount to asking your son for advice on this issue.
Last edited by Kokanee; October 18th, 2009 at 12:30..