I have 11 old cats at home. The oldest one is 10 years old and the youngest one is 7 years old.
Sometime I save kittens from hawkers center. After I neuter / spay, de-worm, and de-flea them, I put their photo in the internet for adoption for free.
My only worry is the cats run away and go missing after they are adopted. That makes me very upset. I wonder whether that is my fault for given those kittens for free. Some people will not care whether the kittens go missing because that doesn't cost them a single cent.