That's not part of the law. If someone wants to fax or mail in a takedown request to Facebook, they have to comply with that too. As several people have mentio

That's not part of the law. If someone wants to fax or mail in a takedown request to Facebook, they have to comply with that too. As several people have mentioned in these topics, the only real issue is Facebook's failure to handle counterclaims properly. That's how the DMCA is supposed to work. You file a copyright infringement claim, the host takes down the material. I file a counterclaim, the host puts the material back up, and it's up to you to sue me. If they just responded promptly to counterclaims, the hand-wringing about bogus claims is mostly irrelevant.