The same is true of any other distributed storage system. Adding a blockchain doesn't change the situation in any way, other than making complying with the law

The same is true of any other distributed storage system. Adding a blockchain doesn't change the situation in any way, other than making complying with the law far less convenient. Though I should add that while the DMCA is indeed a US law, and notification and enforcement mechanisms vary by jurisdiction, other countries also have copyright law. It's illegal to publish copyrighted material without permission in any country with a copyright system. That's what copyright is.