Many of those poor creatures are sweet, gentle family pets. You can tell immediately which ones are vicious and which ones are not. Let the animal rescuers do all they can. Shooting should be a last (and terrible) resort...
I agree. I don't think I've seen a single dog in a TV spot that I would be afraid of. A couple of them were barking at the cameras, but they were just scared, and after tossing them a couple bites of liver, they would be friendly enough, I'm sure.
Anyone who knows dogs well can tell which dogs are to be feared. And it's not very many.
A team from the Oregon Humane Society went into a house and rescued 3 Pit Bulls that were all chained up with no food or water. The male had eaten most of the couch and his chain was wound up in the couch springs and that he had only 10 inches of chain left to move around. They easily rescued the three dogs, having to use bolt cutters on the chains, and carrying the dogs down the ladder.