How do you know feral cats are unsafe? I have 3 that came to use by a feral mom and then she left the kittens at our house where we continue to feed them. They may not allow us to pick them up, but we can pet them and they come by the name we gave them. We were able to trap and spay the female.... however we do not have the money to fix the 2 others.
There are some associations that help, but they can only do so much. When I had trapped my female, they could not help me to get her spayed and out of pocket was 90 bucks that I was not expecting to shell over since I was told they would help me.
If I did not want them here or the others, I would just have to stop feeding them. Why end a life to a poor kitty that had no choice? They are not an issue to us.