My neighbor has a rabbit that I hate, so I sicced my pitbull at it.
You really did that? Why?
Of course I did. It was so funny to see it run, I did not even have to let my dog off the leash.
You're teaching your dog to be violent. Even if it's against another animal, that violence could translate to people.
Some things needed to be done. The bunny was annoying.
You don't sic your dog on anything just because it annoys you, let alone an innocent rabbit.