Source on them being taken without permission? This is being digitized as part of the International Dunhuang Project, which includes Chinese universities such a

Source on them being taken without permission? This is being digitized as part of the International Dunhuang Project, which includes Chinese universities such as the Dunhuang Research Academy. If you're talking about how they would have acquired the scrolls historically, IIRC the maintainer of the cave/temples allowed scrolls to be taken for research/etc in exchange for donations to help restore and maintain the complex.