Pictures That Just Won't Go Away...

From the BBC News site: photos which have been 'deleted' from social networking sites are often still available for long afterwards. In practice 'deletion' actually only results in the link to the photo being removed, rather than taking down the page where the photo is posted - if you type in the URL, you can still see the photo.

Presumably it's true that anyone who had a copy of the URL would have had an opportunity to take a copy of the photo anyway? Still, the fact that it is still out there and 'available' might be regarded as intrusive in any case. Do these companies have an obligation to preserve their user's privacy when it comes to these issues?