The article title is a little misleading: > people’s progress across the structure would be tracked by monitors detecting the Wi-Fi signals from their phones,

The article title is a little misleading: > people’s progress across the structure would be tracked by monitors detecting the Wi-Fi signals from their phones, which show up the device’s Mac address ...I think if you said "mobile phone signal" to someone round here they'd assume you were talking about the GSM radio. If you think shopping malls / cities aren't already using MAC addresses sniffed during WiFi discovery to track location you're sadly mistaken (which is why iOS started randomizing them from iOS 8 onwards).