Ela, I have said further down the thread when you raised this point before, that because of the population of the area, most are willing to have them back on their property. This is a student let area, very inner-city, not a hoity suburb. The main 'carers' of the ferals are shopkeepers, who have them at the backs of the shops, and students, who feed them during term time. The few owner-occupiers (according to recent statistics, 95% of the housing is student lets) put out food during the summer, generally leaving bowls of munchies outside front doors.
Unfortunately, because these cats are no ones 'responsibility' they are breeding. The students admire the cute little kittens, but don't think of the future. Because they are fed, they look healthy. The way to distinquish them from domestic cats is that they run away from humans who aren't their regular carers.
Ela, there would be no problem with releasing the healthy cats back to their territory after neutering. The landlords never visit the properties, neither do the letting management agencies. I know this because I have student housing on both sides of me and it's impossible to get in touch with anyone in charge when I want to (over noise issues etc, the uni housing officer is better at sorting this out with the students).
The shopkeepers like them because they keep down the rodent population. There was masses of concern from the people who worked at the hairdressers, the girls in the chemists, and a guy who lives in the flat over the butchers, when I was doing last November's trapping. Unfortunately, because I had only one trap, the mother became trap-wise and couldn't be caught. She was heavily pregnant at the time. She 'disappeared', probably to have the kittens, before I could trap her. If I could have caught her early in the pregnancy, I would have had her aborted.
If anyone has constructive comments, I'd love to hear them.
Have just had a call from the CP branch I contacted from the link given by Fussy Furball. They were very pleasant, but don't cover this part of B'ham. They gave me the number of my area branch, unfortunately, it's a number I know only too well. They're great at giving vouchers etc, but a choccy teapot when any hands on help is needed!