I like the idea but using a "...unique character string that he says he’s found in the MAC addresses of Google’s augmented reality headsets" seems problematic.

I like the idea but using a "...unique character string that he says he’s found in the MAC addresses of Google’s augmented reality headsets" seems problematic. I thought MAC addresses consist of three bytes vendor ID and three bytes serial number so I'm not sure how you could filter other than on a range of serial number for a specific vendor. That might boot off devices other than Glass.