Apple may have another problem. Privacy watchdogs are demanding answers to this troubling question - Why are iPhones and iPads secretly collecting location data on users?

A report from two researchers, Alasdair Allan and Pete Warden, at a technology conference in California raises questions about how much privacy you implicitly surrender by carrying around a smartphone. It also questions the responsibility of smartphone makers to protect the sensitive data that flows through their devices.

Much of the concern over iPhone and iPad tracking stems from the fact the computers are logging users' physical coordinates without users knowing it - and that information is then stored in an unencrypted form that would be easy to find for a hacker, a law enforcement officer without a warrant... or maybe, even worse - a suspicious spouse.

Apple devices have been retaining this information for some time, but it was kept in a different form until the release of the iOS 4 operating software last year.

Sean Morrissey, a security expert, said on Thursday that the tracking on Apple devices isn't new, or a surprise, to those in the computer forensics community.

Sean Morrissey, Managing Director of Kanata Forensic, said, "This is to help the user use the applications that are on this phone. Because when you’re using anything that has any geo-location data, it needs to know where it is, and part of the function of the certain parts of the operating system and this file constantly let the phone know where I am."

Researchers emphasize that there's no evidence that Apple itself has access to this data.

But in London, privacy campaigners say that if consumers were more aware of the issue, it could affect sales.

Daniel Hamilton, Pricacy Campaigner, said, "If you went into a shop and said I’d like to buy an iPhone'and a sales assistant handed it to you and said 'Before you buy this I need to make you aware that from now on Apple will be able to track everywhere that you go with this iPhone', then clearly nobody would ever buy that product."

Mobile User, said, "I feel like it could be a good thing if I lose it or something maybe, but other than that I think it's kind of weird."

Apple didn't immediately respond.