There are obviously people whose views range from "he's a terrorist" to "he's the best man alive", and everything in between.
A quote from this article as one example of a possible justification:
"Assange himself claimed publication of the cables helped shape uprisings in North Africa and the Middle East and said WikiLeaks was on the side of justice."
If you are of the belief that nothing has so far made much of a difference, there is still an argument that by pushing for more openness from Governments he is helping move towards a better, and potentially more peaceful, future.
A quote from this article as one example of a possible justification:
"Assange himself claimed publication of the cables helped shape uprisings in North Africa and the Middle East and said WikiLeaks was on the side of justice."
If you are of the belief that nothing has so far made much of a difference, there is still an argument that by pushing for more openness from Governments he is helping move towards a better, and potentially more peaceful, future.