Wireless sensors connected to your router that let you know of activity in your house (sms, email, etc). Price: $150.
Combine this with a service of a few strong guys with protective gear, guns and dogs who come over for $250 if they have to do something and $50 for a false alarm, and what need would you have for the police?
Private security firms have been offering such services already for a long time. The only difference is that the only “strong” guys with protective gear available to actually show up in case of intruders are almost always employed by government.
Home insurance is already encouraging such security systems by offering discounts on their premiums. Yeah, it’s hard to see why the security firm or the insurance company cannot provide the “strong” guys also.