Banning the ownership of a firearm has not made bit of difference as far as the criminal fraternity are concerned, all it has done is persecute the law abiding firearm owner(s).
It seems the only way that authorities can see to controlling something is to put a blanket ban on it thus penalising the law abiding members of the community, ie the Scottish goverments attempt to stop binge drinking is to put up the price of alcohol, thus penalising the sensible drinkers in society.