I think an INTJ would have a more coherent point and statement to the public. He seems to ramble, and I can't get a clear read on what he's trying to do. He seems to be confident and logical. There's definitely no feeling, and he seems reluctant to express judgement at all.
I was thinking INTJ but Sarah brings up a good point for INTP. All I keep thinking is 'what is his angle on this?' 'what does he have to gain?'
If he was an INTJ I believe he would have made some demands and the information may not have ever been released. I have no clue what his goal is at this time, so just going by the information at hand, it seems like his main goal is just to expose the truth. Wanting to expose the truth is something I believe many INTPs wouldn't mind doing. Also I've read he is a former hacker. Hackers are typically more INTP than INTJ. INTJs are better at building software and systems, whereas INTPs are more apt to finding loopholes and exploiting the system.
I was thinking INTJ at first but now I'm learning toward INTP until we find out more.
Whatever type he is, he's very stubborn and sticks to his message even after facing imprisonment and isolation from his family and friends by corrupt officials. It's hard to not at least respect his resolve. I believe he's the kind of guy who would tell the powers that be to go fuck themselves even as he's about to be shot in the head.
If he is an INTP, he has some unusually strong Fi resolve going on. Or something else. I can't really figure him out. I would say he could be an INTP but he's quite a tough one, if so. I would have thought an INTP would have stopped this by now to avoid the hassle. He seems driven by a stubborn idealism. So, he could also be an idealist (NF) type.