The personal spy: the smartphone in your pocket may be spying on you, I

There are things you do not want to share with strangers — highly personal text messages, for example, or sensitive business correspondence. Trouble is, these communications are etched on your phone’s SIM card, but invisible on your current handset and thus likely forgotten. You my be upset to know that strangers may easily pick up such personal or sensitive communication and download it to their computers.

Linda Geddes writes that this is precisely what she saw when she walked into a windowless room on an industrial estate in Tamworth, U.K., where three cellphone analysts in blue shirts sit at their terminals, scrutinizing the contents of her phone. “If it’s any consolation, we would have found them even if you had deleted them,” one of them told her.

Embarrassing text messages were not the only thing she had to worry about: “Is this a photo of your office?” one of the technicians asked (the answer was yes). “And did you enjoy your pizza on Monday night? And why did you divert from your normal route to work to visit this address in Camberwell, London, on Saturday?”

Geddes was visiting the DiskLabs, a company that handles cellphone forensic analysis for U.K. police forces, but also for private companies and individuals snooping on suspect employees or wayward spouses. Armed with four cellphones, which she has begged, borrowed, and bought off friends and strangers, she was curious to know just how much personal information can be gleaned from our used handsets and SIM cards.

A decade ago, our phones’ memories could just about handle text messages and a contacts book. These days, the latest smartphones incorporate GPS, Wi-Fi connectivity, and motion sensors. They automatically download your e-mails and appointments from your office computer, and come with the ability to track other individuals in your immediate vicinity. There is a lot more to come. Among other things, you could be using the next generation of phones to keep tabs on your health, store cash, and make small transactions - something that’s already happening in east Asia.

These changes could well be exploited in much the same way that e-mail and the Internet can be used to “phish” for personal information such as bank details. Indeed, some phone-related scams are already emerging, including one that uses reprogrammed cellphones to intercept passwords for other people’s online bank accounts. “Mobile phones are becoming a bigger part of our lives,” says Andy Jones, head of information security