normalize this type of stuff as basic human decency

When human communities were smaller, there was the idea that you’d “run out of town” people who broke the social contract - if you lived in a small town and were known as a cheat or a thief it was more likely that people would just stop dealing with you than having police show up. It’s hard to stay in a place if no-one will work with you, socialise with you or sell you stuff, so you’d typically move to another town and hopefully learn your lesson.

This is obviously a double edged sword; it’s just as easy to end up excluded from society through no fault of your own, but there is definitely something to learn from this. You don’t owe space - physical or virtual - to people who aren’t going to use that space considerately. Society at large is too big to deal with problematic people this way anymore, but in your social circles or smaller groups you can absolutely tell people that if they aren’t going to play by the groups rules then they don’t get to play at all.