Well, as Metchosin pointed out, handguns have not as a class been banned or confiscated in Canada, but various subspecies of firearms, both long and short, have become illegal or restricted over the past 25 years. Handguns, as a rule, have always been fairly difficult to get, and permits to carry them even more so. Yes, there is an underground market and a lot of people have them who shouldn't, but due to its nature no one can substantiate claims about how many there are or aren't.

The gun lobby and all rural firearms owners complain loudly and endlessly about the registration program, and as far as the financial overruns associated with it, they have a point. Is it useful? I rather suspect it is, because its result is less firearms hanging around for no particular reason, and improperly stored to boot. The endless distinction between "criminal" weapons and "law-abiding" ones is simply not based in reality. If guns are more prevalent more people will use them in spontaneous violence, not to mention accidental shootings.   

The recent spate in gang-related gun violence in Toronto reflects the tendency of gangs to conduct business through violence. You can certainly argue that the gun registry hasn't done anything to reduce that type of gun violence, but the notion that it has contributed to it is just plain wacky.