Owners of car navigation systems seem to be suffering a theft epidemic.

At TomTom's NZ launch last week, I related how my sister-in-law just had her Navman GPS stolen from her hatchback - for the second time in months. This on top of one of Navman's new 'n' series systems being snatched out of our Reviews Editor's car while on loan for a PC World test. Scott had taken the trouble to always remove the GPS system from his car at night - and in fact it wasn't on its stalk when he ducked into a shop for 10 minutes - but when he got out a theft had smashed his window and grabbed the hidden Navman.

None of my lunch companions were surprised. The editor of another tech publication said he'd had a Navman stolen out of his car too. And a guy from Geosmart (the AA-owned company that sells maps to both Navman and newcomer TomTom - much more of which tomorrow) said while his GPS system was not stolen, a wannabe thief had seen the stalk (the sucker thing that holds it to the window) and smashed his car window on a fishing expedition.

Wow. Admittedly my sample of people who use in-car GPS systems is not huge. But every single one of them has been targetted by a thief.

Incidentally, only commercial systems used by truckers etc have a transmitter as well as a receiver, which would allow a stolen system to be traced (sorry, Natalie). Not that the boys in blue are working shifts to solve this problem. The editor whose GPS was nicked actually managed to grab the thief's license plate number and immediately called the police - but apparently they weren't interested.