What a load of nonsense. You can't just take someone else's pet!
@Onemoretune
Brasty - I bet the “ownership” would suddenly revert back to the original owner if said cat needed £4000 worth of veterinary treatment...
This ^
@brasty
No, I have a friend who have a cat that came to live with them, and they pay all the vets bills
So, it still belongs to the other owner, but the people who have stolen the cat and now say it's theirs, have pay all the vet bills?
I am really struggling to believe that.
If someone stole any of MY cats, I would call the police. I am pretty sure I know whose side they would be on. The cats are registered on their microchip at MY address, they are registered at the vets at MY address, and I still have the receipts and paperwork from when I got them from Cats Protection. So you're deluded if you think you would be allowed to take my cats.
Why the hell are you encouraging cats around your house and feeding them anyway brasty? Get your own bloody cats! 
And to you and the people saying you can just take someone else's cat because no-one owns it (apparently,) you are talking crap. Educate yourself
www.pets4homes.co.uk/pet-advice/your-pets-and-the-law.html
From the article...
The law regarding theft of owned pets
The Theft Act of 1968 covers companion animals, and if your cat or dog is stolen then you have the same legal rights of recourse as you would if anything else you owned was illegally taken.
In an instance where an animal is lost or strays, the pet is still considered to be the property of the original owner, and anyone who finds a lost pet must make reasonable endeavours to do everything possible to locate the original owner and return their pet to them before any provision for permanent re-homing can occur.
The Criminal Damage Act of 1971 also considers it an offence in contravention of this act if any person deliberately harms or kills an animal belonging to another person. This is in addition to the Animal Welfare Act clauses as stated above.
brasty
Look you choose to get a pet that is famed for its independence and doing what the fuck it likes. Sometimes what it wants to do is live elsewhere.
Stop talking drivel. You're embarrassing yourself. You can't just take someone's pet, or start feeding it, so it chooses you. It's a bit pathetic actually. Like I said, get your own cat!