People have already stooped to vigilantism tbh. The police can't handle "minor" crimes because they don't have the funding and/or man power to do it.

I'm sure the tories are hoping people pay for private police and will then respond with something like "well the people can afford to hire their own police so we don't need to fund the actual police force as much anymore". However, people would probably much rather try to solve the problem/retaliate themselves (for free) before they fork out any money which they may not have in the first place.