Researchers from Cambridge University have found that many photos were still accessible on a number of social networking sites including Facebook, even after having been deleted.
The researchers reported that Flickr and Google's Picasa performed better, while Microsoft's Windows Live Spaces removed the photos immediately.
A Facebook spokesperson stated: "When a user deletes a photograph from Facebook it is removed from our servers immediately. However, URLs to photographs may continue to exist on the Content Delivery Network (CDN) after users delete them from their Facebook, until they are overwritten. overwriting usually happens after a short period of time".