We sometimes get emails from people who have taken in a lot of cats and have problems maintaining them. I do know that these people do so out of the kindness of their hearts and they want to do the right thing, but there comes a point for all of us where we have to stop.
What often happens is that the person may have bitten off more then they can chew. They take in a lot of cats, and after a while they feel they cannot afford to sterilise them. This of course leads to more mouths to feed. In the meantime, if the number of cats gets very large (which it will), there is a problem with maintaining hygiene and health of the cats. There may be complaints of smell. The cats may start getting sick and/or stressed and start passing diseases to each other. At this point, the person may not be able to afford veterinary fees for the cats. What started out as a cat rescue, may well result in the death of the cat. The cat may have a 50-50 chance on the street, but if it goes into a house full of sick, stressed cats where veterinary fees are not available, mortality rate is going to be a lot higher than if the cat has stayed on the street.
I often hear from these people that they were unable to say no. Most of them are just very nice people who want to help out and cannot turn away someone or some cat in need, but sometimes the best thing you can do is to refuse to help - both for you, your cats and even for the cat in question.