I suppose you can ironically point out that this guy thinks he's some kind of revolutionary which is some peoples' justification for their support of the right to bear arms but at the end of the day this is pretty much another "guy gone crazy" scenario.
Well, assuming he is telling the truth in his manifest, would that not give him the right to?
Again, if true, it seems every other possible course of action has been tried or denied already. What do you do when crimes go unpunished and the only thing left is force?
Actually, reading the thing made me think of something I heard or read somewhere: "Monsters aren't born, they're made."
Just to be clear though, I don't support the killings. Especially the family members of those he says are corrupt.
Killing is bad, but killing innocents is just so much worst...