Too many Americans are afraid to take steps to protect themselves for fear of getting in legal or civil trouble or being seen as "impolite" or racist.
To be fair, after the first night, it was pretty obvious that the police wouldn’t be coming around to investigate any time soon. I think it takes a lot less to do what needs to be done in a “no rules” environment than it does in a more normal environment where the cops will promptly show up to collect your arse and ruin your life.