There's an obvious privacy/trust issue that has already been solved by cloud photo sharing. I've seen it in Flickr and OneDrive: both of them allow one to selec

There's an obvious privacy/trust issue that has already been solved by cloud photo sharing. I've seen it in Flickr and OneDrive: both of them allow one to select a bunch of items, or a folder/album, and generate an URL key that allows access to only those items. Actually, having that in mail systems could be rather useful for many other work flows.