Nope. Its real. Talk to any security officer in shopping complex and they'll tell you.
JB Sutera Mall security department caught one of this thief few months back. I went to backup their CCTV footage.
Local thieve are not using RF scanner. They uses a RF listen in device like a MP3 player that can be pre-tune to the right frequency of what laptop bios is omitting. And it can correctly detect which brand of laptop it is. The device will give a weezing sound omit via ear phone.
Let say today target is Sony Vaio. They get an actual Sony Vaio and uses that detecting device to tune in front of the laptop till it detect the frequency and omit weezing sound. Then off they go for fishing in the car park. Each manufacturer has different range of bios frequency. Or I should say dfferent bios manufacturer, like Amibios, Pheonix..... .
So whenever you see someone wearing sort of MP3 player or Bluetooth Earpiece loitering around carpark, you might want to give this fella extra attention.