How can people do this??

We got 2 new puppies in the dogshelter yesterday. They were found tied in a carrier bag by the side of the road....suffocating!!!! The 2 puppies are soooo sweet but they are very scared now... we are cuddling them constantly to make them feel at home in their new home and with their 38 new small friends.
How can anyone do such a thing? Really make me so angry!
Pictured below is one of the poor puppies.