Thieves in San Francisco take advantage of the first one to check if there are goods in cars.
Have you seen how these people work? They drive up, stop next to a car, tap the window with a window breaker, pull the chair down to look in the boot, grab anything they find, then drive off.
In and out within a minute. No time to be dicking around with Bluetooth scanners to see if there are MacBooks around.
Suffice it to say I have talked, personally, to enough bippers to understand that there are 'spotters' and 'bippers', and which one uses the cell-phone based Bluetooth scanner (which requires no 'hardware' or 'effort' to figure out the source of a BLE signal.)