A hacker has demonstrated in a live webcast how the iPhone tracks its user's entire web history.

Everything users look at gets snapped, he said, including GPS maps, email, stocks and even their web browser.

Jonathan Zdziarski, known as 'NerveGas' in the iPhone development community, wrote a book on how to break the iPhone security and has followed this with a live guide aimed at law enforcement agencies on how they can bypass the iPhone 3G's passcode lock by creating a customer firmware bundle.

The webcast, hosted by O'Reilly Media, took place yesterday and will be available for those that missed it in a few days, according to Zdziarski.

Zdziarski told vnunet.com how the iPhone stores all its user's actions. "Whenever an application is suspended, the iPhone takes a screen grab and temporarily stores it on disk," he said.

"This can happen whenever you push the home button, receive a phone call, or during other events where the iPhone puts the application you're using on hold. "

Zdziarski added that, although it seems as if the screenshot has been deleted, it can easily be recovered by a forensic examiner using a data carving tool "such as scalpel or foremost".

He claimed that there will be hundreds of these screenshots on "any given device".

"This practice seems to be in place across all versions of iPhone software from v1.0 all the way to the current 2.0 software," he said. "I haven't checked out 2.1 yet, but I suspect it hasn't changed."