true ferals should be altered and released back to the wild, hopefully with someone to feed them on a regular basis.
I agree wit PayItForward. TRUE ferals almost always are beyond being socialized. And taking them to a shelter is an ultimate death sentence, since they cannot be placed.

I have worked with feral kittens, from ages 6 weeks to 4 months. It takes a special person with patience and commitment to be able to bring them out of their feralness.

The ones that have been feral for years should be fixed and put back out where they feel comfortable with other ferals. I have a friend who maintains feral colonies. All of the cats have been spayed/neutered, vaccinated and ears notched and she goes around putting out food and keeping the feeding stations clean and the "shelters" (they're made of Rubbermaid bins) camouflaged and in good condition.

Some of the cats have been around for years.