There's actually a potential line of attack that rose due to two SCOTUS decisions a few years ago. The Eldred and Golan cases essentially established that fair

There's actually a potential line of attack that rose due to two SCOTUS decisions a few years ago. The Eldred and Golan cases essentially established that fair use is constitutionally necessary in order for copyright to coexist with the 1st amendment. If the DMCA is found to hinder the effective exercise of a fair use right, it could be struck down (either facially or in an as-applied challenge)