I'm unsure if this outage is the result of their doing. However, @Nykisnottrans pointed out possible connections between Liz Fong-Jones with threats to DDoS ISPs that the Kiwifarms is on. I believe that is a threat to damage a computer which is a crime under 18 U.S.C. 1030(a)(7)(A). PATRIOT Act makes the impairment to the integrity or availability of data, a program, a system, or information a part of the definition of 'damage'.
We know that Liz will do everything outside of the law to shut down this forum, including illegal activity. Liz is outside of the US but is attack a US based website owned and operated by a US citizen. That means that this is Fed jurisdiction, most likely the FBI. And if there is one thing the Feds want, it's an easy win when pursuing a criminal case. If we can provide evidence of every single federal criminal offence that Liz is doing, someone is going to have to look at. The more thorough our evidence is, the better chance of them pursuing the case. And even if they decline to pursue the case, somewhere in the FBI database is going to be a file on the allegations of Liz Fong-Jones's criminal behavior towards Kiwifarms.