[weinzierl]

The technical side is a solved problem, the legal side not so much.

You practically cannot preserve and make available something if the copyright holders don't want you to. If the copyright situation is complicated you bear the risk.

You can say, that this is how it is supposed to be, but it is not like it works in the non-digital realm. You could argue that we'd need something like digital monument protection, where artifacts can be preserved against the copyright holders will.