The max headroom TV signal hijack guy was never found... and THAT was a high profile prank.
Hadn’t heard of this, what a strange read
If this is (as it appears it might be) simply a reflection attack of some sort, I'm not sure what crime could've been committed. Or at least what computer crime could've been committed. Impersonating a federal official is about the only thing I can think of.
I want to live in the techno-libertarian Utopia you think this is
This would get the book thrown at you in any court of law. Hacking FBI email servers is what happened. The IP and subdomain are FBI.
Like it or not, this seems like a pretty easy CFAA case. Sending email through a server you're not permitted to access sounds like it would constitute a CFAA violation.