Why don't you want the police to be able to find your when there's a crime? What if you're the victim of a kidnapping? Or murder that goes unsolved because Google wouldn't tell them who did it?
The incident rate of kidnappings is so low that it's not anywhere close to ranking in the first volume of "List of Things I Worry About".
The government abusing data it collected on its citizens to silence dissenters, however, is something I've seen on a daily basis. And so, we set priorities.
My main concerns are how such tools may facilitate automated injustice, as well as providing the means for heavy-handed political/intellectual influence and control.
