You didn't understand what I wrote. You can break copy protection if you own the rights to a work. This means you can e.g. circumvent Window's license checking if you own a copy of it already. The DMCA does not criminalize that, nor could it, and this is probably why py-kms is still up on github after a copyright challenge.

This was a change that I am assuming was added before any complaint could be mounted about this use case for fear of striking more of the DMCA down than just that provision that was modified.