I'm not saying I'm necessarily against what Wikileaks are doing, but they seem to be a self appointed organization who decide themselves what information they will release or withold. Some of that released information could stir up old grievances between governments. What gives Wikileaks the right to have such responsibility?
Furthermore, Wikileaks are pretty sensitive themselves about any investigations being done into their own business. Their founder, Assange, is still in hiding, and is currently being sought by the Swedish police on a charge of rape.
As far as the motives of hackers goes, I would have thought that your average hacker gets his kicks from the success of breaking into someone's computer, not from some altruistic desire to reveal the 'truth' (whatever that may be) into the public domain.
I wouldn't assume that Wikileaks are necessarily the 'good guys' here.