The main reason so-called 'breed ban' legislation doesn't work is because it's impossible to come up with & agreed upon & legally enforceable 'breed' definition for what's actually a very general type of dog.
Additionally, such laws grossly violate the rights of the otherwise law-abiding vast majority of dog-owners and, as they advocate arbitrarily killing animals based soley upon ignorance & hysteria, are - by definition - morally bankrupt.
Accordingly, to the best of my knowledge, there isn't a single reputable animal welfare body in all of North America - from the seeing eye dog folks to humane societies - which supports so-called 'breed ban legislation'.
As both examples & to offer legitimate solutions to the problem:
click here for full sized PDF of above
And who supports 'breed ban' legislation ???
Beyond knee-jerk liberals & a handful of statist control freaks on FR, none other than the ecco-impirialist, earth-worshipping, social fascists of PETA - & also see: A Letter To PETA .
click for bomb dog Neville's
'saved from Ontario's social fascists' bio