This was in my ISP's monthly newsletter - interesting and more than a little worrying. If this concerns you, check out the link, which includes instructions on how to disable geo-tagging on various smartphones.

'Cybercasting' - the ability to locate people and things via the photographs they post online from digital cameras and smart phones, including the iPhone, that automatically geotag images by embedding the longitude and latitude at which they were taken.

A new Web site demonstrates how easy it is to display this hidden information by listing photo-accompanied tweets as they happen and revealing where the posters are. Explaining the site's purpose, its designers say that if people realised how much information they were posting each time they clicked "send" on their phone to post a photo online they would stop doing it.

"Disabling geo-tagging on your phone is easy", say the site's originators. "We want to make people aware what they are posting when sending out their photos and to show them options to disable that functionality".

I Can Stalk U - Raising awareness about inadvertent information sharing