That's an interesting point. A major complaint about DMCA has always been that it allows copyright owners to criminalize otherwise legal acts by adding DRM. But

That's an interesting point. A major complaint about DMCA has always been that it allows copyright owners to criminalize otherwise legal acts by adding DRM. But the usual examples have always been fair use rights, like making quotations, or researchers and libraries trying to preserve historical documents. Those uses have always been "collateral damage", which the copyright owners didn't wasn't specifically interested in preventing. But with this ruling, it is now clear that the thing that region codes aim to prevent would be completely legal except for the DMCA's circumvention provision. So in some sense, this is a much more blatant example of copyright owners writing their own laws.