>How do you establish that a given act of hacking is or is not a public service?
If you hack and then publish embarrassing material to the whole world it's a public service.
If you hack non-embarrassing operationally sensitive material and then leak it selectively to foreign governments then it's espionage.
There's some fuzziness but it's not a bright line to cross and Julian Assange is very, very far away from it.
The fact that the murders that were uncovered are still going unprosecuted adds considerable weight to the idea that it was a public service. If Assange had done the exact same thing to Russia the idea that it was espionage would be justifiably mocked. It's not mocked because nationalism is a potent drug, essentially (here, it's not like Russians aren't looking at this and shaking their heads).