I've seen DMCAs take down GitHub repos where the code was a clean room reimplementations of proprietary software.

I know entrepreneurs who have used them to take down phishing sites that mimic real corporate websites and feature the photos of those involved in running the legit company.

Funny example, every time I've had to do this GitHub refused to take down forks based on a bullshit argument that it's impossible to do even though you can just look for matching SHA hashes. I wonder if someone will dismantle them in court for that someday...