Next step is to just build a script that parses the DMCA takedown notices here[1] and automatically builds a block list out of those domains.
https://github.com/github/dmca
you'd have to differentiation between a legitimate DMCA takedown vs a false claim...may be some NLP on the work being taken down to see if it falls under fair use?
I don't think this needs to be that complicated. If I'm understanding correctly, the DMCA takedowns in this case are against pages blocked by EasyList. You would just have to correlate DMCA takedowns with historical EasyList filters.
