Great question with interesting first answer.

Very good comment at The Economist:

The basic question is not whether we think Julian Assange is a terrorist or a hero. The basic question certainly is not whether we think exposing the chatter of the diplomatic corps helps or hinders their efforts, and whether this is a good or bad thing. To continue to focus on these questions is to miss the forest for the texture of the bark on a single elm. If we take the inevitability of future large leaks for granted, then I think the debate must eventually centre on the things that will determine the supply of leakers and leaks. Some of us wish to encourage in individuals the sense of justice which would embolden them to challenge the institutions that control our fate by bringing their secrets to light. Some of us wish to encourage in individuals ever greater fealty and submission to corporations and the state in order to protect the privileges and prerogatives of the powerful, lest their erosion threaten what David Brooks calls "the fragile community"—our current, comfortable dispensation.