I really dislike the new standard of making location tracking opt-out, not opt-in.
There's a startup that tracks the location of customers across stores using the MAC addresses of their cell phones, without their knowledge. In order to opt-out, you have to register your MAC address with them: http://nomi.com/privacy/
The key to both Nomi and (to a lesser extent) Google is that users don't even know when they are being tracked. Opt-out only makes sense when there is a reasonable expectation that the user knows that the tracking exists.
There's a startup that tracks the location of customers across stores using the MAC addresses of their cell phones, without their knowledge. In order to opt-out, you have to register your MAC address with them: http://nomi.com/privacy/
The key to both Nomi and (to a lesser extent) Google is that users don't even know when they are being tracked. Opt-out only makes sense when there is a reasonable expectation that the user knows that the tracking exists.