An employee of Wiko telecom company holds a smartphone, on April 11, 2014 at the company's headquarters in Marseille

Mobile security startup Lookout is turning smartphones and tablets against gadget thieves with a new feature that—when possible—will snap a picture of the culprit.

A new theft alert function added Wednesday to Lookout's for Apple and Android mobile devices sets out to pinpoint where a gadget might be and, in some cases, even take the thief's picture.

"We are not providing this information for you to go out and find the device yourself," Lookout product manager Greg Lou told AFP.

"It is so you can give it to the police so they can find it for you."

A premium version of Lookout costing $3 a month or $30 annually already provides features such as backing up data and finding lost phones.

The new capability lets users tell smartphones to fire off theft alerts if anyone botches a lock-screen code, turns the gadget off, pulls a SIM card, or puts the device in 'airplane' mode to block network connections.

On Android devices, theft alerts will signal front-facing cameras to snap photos in the hope of capturing images of culprits.

The capability referred to by Lookout as taking a "theftie" is not available on Apple devices because the operating system won't allow it, according to Lou.

Emails that include maps of the location of stolen devices are fired off to owners. In the case of Android, the emails include copies of "thefties" taken with front-facing cameras.

"Phone theft is becoming a really big problem," Lou said.

Lookout launched in 2007 and reports that 55 million people worldwide use its software, a version of which is free.