The ASPCA has come out as being apposed to breed specific bans just because of problems that could arise from the bans themselves and the bans not being effective.
The American Kennel Club is also against breed specific bans because they realize that it does not target to true problem.
The Association of Professional Dog Trainers also does not think that breed specific bans should be put into place because it would not stop attacks because breed is not the only factor in attacks.
And these are only a few of the organizations that are against it. Others include the Canadian Kennel Club, the SPCA, the American Veterinary Medical Association, and many humane societies and veterinary societies.