TFA: "The app brings up the (scanned person's) vital information, including name, ethnicity, gender and address (..), the address of the hotel where they are

TFA: "The app brings up the (scanned person's) vital information, including name, ethnicity, gender and address (..), the address of the hotel where they are staying and information related to their internet usage." Wow. So just by looking at you, they can see how often you visit Hacker News - or what else. Scary as.