We want to put a KILL SWITCH into your PHONE, say Feds

The only good mobe is a dead mobe

US law enforcement is calling for a mandatory kill switch on all mobiles, enabling the shut down of stolen phones in the hope of rendering them worthless.

Mobile phone theft keeps rising, with one in three US robberies involving mobile kit, apparently. A coalition of US law enforcement agencies calling itself "Secure our Smartphones" is therefore calling for manufacturers to take responsibility for their products – to the point of reaching out and locking them down if they get nicked.

This plays nicely into the hands of Apple, whose latest mobile OS (announced last week) coincidentally has exactly that feature. Samsung has promised something similar, and both Google and Microsoft came along to the Smartphone Summit to talk about the idea.

And it's not a bad idea. Yet, like all “not-so-bad” ideas, the devil is in the detail.

To reach out to a stolen phone it has to be identifiable, beyond the easily-changed mobile number. All (GSM) phones have an International Mobile Equipment Identifier (IMEI - press *#06# to see it) number, and the majority of mobile networks subscribe to a system which blocks stolen IMEI numbers from their networks.

That system, known as the Central Equipment Identity Register or CEIR, theoretically makes stolen phones useless, but this is assuming that the IMEI hasn't been changed, the handset isn't shipped to a developing market which hasn't coughed up the CEIR fee, and (perhaps most importantly) that the thief knows all this.

Most UK muggings, for example, include the theft of a mobile phone, but it's rarely the phone the thieves want. They've read about tracking and hidden camera apps, and few of them have the technical nous to spot such a thing.

The purpose of stealing the handset and then discarding it is to delay pursuers, thus providing more time during which stolen credit cards and other spoils can be turned into cash.

But that can skew the crime figures, making it look as though mobile theft is reaching the epidemic proportions described by New York Attorney General Eric Schneiderman.

That's not to say stolen phones are without value. Changing the IMEI of a phone is illegal in the UK (even advertising one's ability to perform the act is against the law) but on most handsets it remains possible.

Once it has been changed, the phone can be used anywhere. Failing that, there's always a market in the dwindling number of countries who've not yet implemented CEIR, despite international pressure.

Manufacturers could make it all but impossible to change the IMEI. That would address many of the issues, but it wouldn't give them greater control over their customers and an excuse to stay in touch throughout the life of the product (“send in your warranty documents or we'll kill the phone, and be sure to tell us if you decide to sell it on”).

For Apple this is perfect, and the timing couldn't have been better – though the consortium is reserving judgment on iOS7 until it has been seen in action.

The surprise absentee from the list of firms considering implementing a killswitch function is BlackBerry, whose infrastructure and customer relationships makes this eminently practical and already available.

But if one discovered that thefts of BlackBerry devices were just as high as the rest, that would make this whole "Save our Smartphones" consortium look like a pointless political exercise. Perish the thought. ®