Nope, definitely not "most" phones. iOS 8 randomizes MAC addresses, but probably not often enough to stop this from working: http://blog.airtightnetworks.com/io

Nope, definitely not "most" phones. iOS 8 randomizes MAC addresses, but probably not often enough to stop this from working: http://blog.airtightnetworks.com/ios8-mac-randomgate/ http://blog.airtightnetworks.com/ios8-mac-randomgate/ And of course you would only need a sample of passengers with static MACs for this to work.