How could people do this.....??

On stoppuppymills.org... (on the main page) they have 3 videos (the first on Pets of Bel Air, the second inside of a Puppy Mill, and the third about Dog Auctions) that are so sad... How could people buy and sell dogs like this? What do you think of this... (I reccomend watching these videos on a href="http://stoppuppymills.org)???" rel="nofollow"http://stoppuppymills.org)???/a