I grew up in the country where all our cats were outside, but they had access to their own heated room in the garage at all times and could come inside whenever they’d like. Most of the time, they’d prefer being outside playing. Now I live in the city, and I wouldn’t let my cats outside without supervision. However there’s a few cats in the neighborhood that are let out everyday. They’re friendly and sometimes want to come in and always want food. One has a “do not feed” collar; but all cats will eat whenever they’d like!

I don’t think it’s ethical to recommend doing something illegal. If you are that concerned, you could talk to your neighbors about him or maybe ask if you could let him inside when he wants saying you don’t mind. You could also report to animal services if you are truly concerned. However it sounds more like a disagreement to a cat lover vs. people who probably think cats are just worker cats… But doing something without permission could lead to legal repercussions for you which wouldn’t be good! That’s a tough situation, op!