This is what can happen when people list pets as free to a good home.
Quote from a dog fighter
“The hardest thing is to get enough dogs and cats for baiting. One good source is the local newspaper that offer a cat or dog for free. My wife dresses up neatly and collects them for me. If that source is running dry we just hire local gang kids to fetch dogs and cats. They scour the backyards and alleys and take whatever number we need. They make sure they leave the doors or gates open so people just believe they accidentally left them unlatched and that’s how their animals got out and got lost.