As a thought experiment, I've been pondering how we need to change our police and how we can with some of this technology. Wearables seem novel and like they could very easily be factored in as evidence in certain crime situations, it seems like it has to be after the fact though. More fundamentally, with cameras and the different recognitions and perhaps a few other sensors, I cannot imagine a case where we wouldn't be able to detect weapons in a crowd in a public space, maybe within the next 15 years.
Say for example you could, with a high degree of confidence, identify the absence of guns in a crowd or report that n people out of this crowd are most likely carrying weapons, you could instruct the police on how to engage them, whether or not they need to have lethal weapons or not. Likewise, maybe even as a service, you could be notified if there were too many weapons in your vicinity or something to that effect. That seems like a very interesting and increasingly possible service. Is concealed carry protected as a privacy? There will be some interesting problems, the militarized police will likely never want to relinquish their weapons, even if they knew there were engaging unarmed people, I have no idea what their excuse will be (other than weapons help them to present an image of power and authority) And I suspect that concealed carry folks will be upset of others around them know about it and react to it. There will be some interesting policy challenges and this stuff seems like it is almost certainly coming down the pipe.