some times my friends cat stay out all night and the people over the road feed her,she aint got a collar on cause it rubs her hair off.so i think you could of took someones cat ,thebest thing you could do is ask the people who are feeding him whos cat it is, but if it aint anyone sounds like she/he will be really looked after by you,but its just best to make sure because i wouldnt like anyone taking my cats away.