The statement from the ISP sounds like the feds actually seized the physical server. Sounds more like suspicion it contained encrypted kiddie-porn or jihadi material than a DMCA action. Remember the DMCA link is only speculation. Screen-shots and downloads as proof, plus a cease-and-desist order would have sufficed for DMCA enforcement, though I suppose encrypted versions of copyrighted material might make them want to seize the physical server, too.
Now here’s an idea: drive the Feds mad by setting up sites containing encrypted files with completely innocuous public domain content, but file names suggestive of something nefarious, and generate lots of traffic to and from it.
Hahaha! Use crazy encryption schemes that take them weeks to crack!