Running a service primarily for legal purposes that some criminals can take advantage of is pretty different with regards to intent than reviving an old domain name that you know is primarily used by old illegal torrents as a tracker.
I spent a few minutes googling, and it seems like that at least as of a decade ago the exact bounds here weren't well defined: https://www.scotusblog.com/2014/03/opinion-analysis-justice-...
> Finally, the possible liability for an “incidental facilitator” – such as a firearms dealer who knows that some customers will use their purchases for crime – is noted but not resolved. Thus, thankfully, there is still some fertile ground for hypotheticals with which we practicing law professors can bedevil our students.
Here it's not the "mere fact that somebody could use your tracker for piracy". It's that you're literally observing that a bunch of old mostly-piracy torrents are pointing at this domain, and then deciding to turn this domain back into a service which assists in that piracy.
It's kind of like Kim Dotcom's defence of his systems where he was saying that he was making attempts to remove content from his systems in compliance with DCMA requests. That is, the claim is his systems were legal because even though people were using them for illegitimate purposes, he was actively working to prevent that from happening.
