Why would a person do something bad like this? Well, there are several reasons, and I will tell you some of them.
(1) People might want to sell the dog over the internet or at a flea market or someplace and make money.
(3) They might just want a dog for themselves or for their kids, and they don't want to pay to buy or adopt one.
(4) They might want to use the dog as a "bait dog" for dog fighting.
The AKC says that in the first 7 months of 2011, 224 dogs were reported stolen. In the same 7 months of 2010, only 150 dogs were stolen. The total for 2010 was 255 dogs, which is up from 162 in 2009 and 71 in 2008. The reason for this increase in dog-nappings is probably due to the bad economy and people looking for ways to make money.
So anyway, those are the sad facts and warnings about how your dog could get stolen, which is something you don't want to happen, of course. And since your dog doesn't want it to happen either, he or she will thank you for watching out for dog thieves!