Chicago to extort money to "sponsor" off duty police patrols

The police are minutes away when seconds count. But now Chicago wants people to pony up extra  cash to sponsor increased police presence in their neighborhoods. If only there was a way for people to get most of the benefits of police presence without having to pay extra. Like a one time purchase that you could carry with you, that would give pause to would be attackers. I'm at a loss for what it could be...