Sad reality is that the stakes for security seem to be much higher...if criminals or terrorists can coordinate and leverage instant information, the only way to 'connect the dots' for an actor that doesn't act blatantly suspicious is to track unusual activity over a wider view (via digital profiles). Biometrics - be they visual such as a face and fingerprint, or traits such as a walking gate and voice signature, all add opportunities to identify individuals. Machine Learning has dramatically expand the scale of data points that can be connected. It's been available to governments for some time, definitely not a decentralized reality. Perhaps one day we can use this to re-establish the sense of community relationships that are lost when we interact in large anonymous environments.