Apple iPhones and 3G iPads are secretly recording and storing details of all their owners' movements, researchers claim.
Location data is kept in a hidden, unencrypted file according to security experts Alasdair Allan and Pete Warden.
With the right software, it can be used to map exactly where a person has been.
Apple has yet to comment on the revelation, however there in no suggestion that it has been uploading or using the information.
The findings, first reported by the Guardian newspaper, will come as a surprise to most iPhone users, as their devices do not give any visual indication that such data is being recorded.
However, although the practice is not explicitly flagged-up, it appears to be covered in the company's terms of use.
"We may collect information such as occupation, language, zip code, area code, unique device identifier, location, and the time zone where an Apple product is used so that we can better understand customer behaviour and improve our products, services, and advertising"
more at
http://www.bbc.co.uk/news/technology-13145562