Predictive policing systems seem like they will be very difficult to properly validate. On the one hand, it could go like the drug industry where there are bodies "testing" potential solutions, but the money, incentives, and sheer noise make the results highly suspect. On the other hand, cities and towns may prove to be a good experimentation framework, in the same way that laws are "tested" at the country/state level. I'm curious to see if much useful will come out of this, and how long it will take.