We live on the same street as BIL and SIL. Recently there have been two adorable kittens in the garden. I admit I once fed one of them because he was behaving as though he was really hungry, but now I know they belong to someone, I haven't done it again and won't. I know my cats do a good job of pretending they never get fed, even quite soon after dinner!
SIL is falling in love with the kittens and is tempting them into their house with food. She's got flea treatment for them and is now talking about putting collars on them.
The person they belong to has a boyfriend with a reputation for violence and unpredictable behaviour. I don't know how true that is, but it's the "word on the street." Either way, I think trying to nick somebody else's cats is not on, and the woman will be justifiably pissed off. AIBU?
BIL doesn't mind cats, but doesn't want one.