The second issue that I see is that someone has to take the liability of
housing thousands of copyrighted images, even if they are only available on
a temporary basis. Not many people (including hosting companies) are going
to want this liability. You can mitigate the risks by making the site
non-indexed, require a login, etc. It's still not a small hurdle, I don't
think. And it would obviously involve a lot of bureaucracy if an already
established organization was involved, like Wikimedia.
that would be facebook or flicker.