Four out of five iPhone users have enabled a feature that allows them to locate, lock and wipe their phones if they are lost or stolen, according to the results of a survey by the San Francisco district attorney's office.
The survey was conducted over the first two weeks of November as part of District Attorney George Gascón's push to get smartphone makers to address the rising problem of smartphone theft in major U.S. cities.
It was advertised by the district attorney's office through social media and attracted 347 responses. While the survey lacks a wide sample base and is skewed towards social-media users, it found 245 of 313 respondents -- 78 percent -- had Apple's Find my iPhone with an activation-lock feature enabled on their phones.
The software lets iPhone users see the location of their phone on a map, lock the phone and remotely erase personal data. A new version supplied with Apple's iOS 7 operating system includes an activation lock, which keeps the phone from being unlocked, wiped or erased by a third party without the input of a passcode.
Gascón has been pushing smartphone makers to include just such a lock in their phones. He believes that if smartphones can be rendered useless after they are stolen, their resale value disappears and so does the incentive for theft.
The district attorney commended Apple on its introduction of the feature but said more needs to be done.
"Until Activation Lock is fully opt-out, it appears many iPhone owners will not have the solution enabled," he said in a statement. "This leaves iPhone users at risk, as thieves cannot distinguish between those devices that have the feature enabled and those that do not."
Smartphone theft is a growing problem in large cities across the U.S. Users often have their phones snatched from them while in public, sometimes after being threatened with guns or knives.
Gascón and Eric Schneiderman, the state attorney general for New York, are spearheading efforts in the U.S. to get smartphone makers and cellular carriers to tackle the issue. The two have been in talks with Apple, Google, Samsung and Microsoft since earlier this year about activation locks. Apple responded with the new functions in iOS7, and Samsung has begun installing a security app on its devices that users can pay annually to activate.
Earlier this month, Schneiderman sent the five largest U.S. cellphone carriers each a letter asking why they are opposing the installation of a "kill-switch" device in their handsets as a deterrent against theft. The letter alluded to possible collusion among the carriers on the decision.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is email@example.com