> Some people may even switch off their phones when they will come to know that they are getting tracked. They don't need to count each and every person to det

> Some people may even switch off their phones when they will come to know that they are getting tracked. They don't need to count each and every person to determine relative wait times, as long as the portion of wifi-enabled travelers is roughly the same in each area. > Another reason for their system's inaccuracy is - not many people use airport wifi. Most of us have data plans. You don't have to be connected to the airport's wifi for this system to work. The phone's wifi radio just has to be turned on.