You would be surprised the number of people that think that setting a cat or dog "free" is ok.
My little cat Clyde was one of those cats. His owner decided to let him go, at age 2 months because he was refusing to use the litter box. Can't say I blame him though, the litter box was beyond filthy. She was going to take him out to the country and drop him somewhere because she thought he was too wild to be trained. I took him from her, and he turned out to be a wonderful cat, never once had an accident because I kept the litterbox clean for him. He was in pretty bad shape when I got him, he had dry, dandruffy fur from poor food, and a terrible case of worms.
I just can't fathom what would make a person think that a domesticated animal could possibly survive out in the woods.