I am not so sure. Fans in other cities likely won't hear much about it. Not selling liquor would be a good start, as idiots always get more idiotic with a little bit of liquid courage, but that would never fly as arenas make too much off of sales. Having big signs or announcements when entering all arenas that anyone throwing anything at players and/or on the court will be banned for life and arrested wouldn't be a bad start. Just spitballing. Even though they are not in the wrong here, probably wouldn't hurt as well to let players know that the punishment will be harsh for going into the crowd and after fans who do stupid stuff. That is the kind of stuff that can lead to another malice. If the fans cross the line, let security and the authorities handle it.