It doesn't have to be all wrong or all right.
The problem with Collateral Murder isn't that Manning leaked documents to Wikileaks that then embarrassed the USG. The problem is that the U.S. military murdered a bunch of civilians, then murdered people who tried to help the victims.
The public indeed needed to know about these civilians being killed. However, the public did *not* need to know what ambassador is calling what head of state an asshole. The idea was supposed to be WikiLeaks giving the data to journalists who then decide what to publish. That is exactly what happened to the Snowden documents, but WIkiLeaks fucked up and put it all out there.
The problem with Wikileaks publishing Podesta's emails isn't the violation of his privacy (funny how Dems suddenly give a shit about privacy after years of defending Obama's warrantless surveillance programs), it's that Podesta was part of a corrupt organization of elitist assholes bent on rigging the general election as well as their primary.
Again, if only a few bad emails (like biasing against Bernie Sanders) were made public then there would have been nothing to say here. What's bad was making public everything, including the stuff that had no public interest. In some way, it was even counter-productive from the PoV of hurting Clinton since there was so much information that anything really bad just just buried.
Again, the way to do leaking is to have a *filter*. You publish the relevant/bad/incriminating stuff and you leave alone the boring stuff or the stuff that can cause harm to other people without being public interest. Just imagine if Snowden had sent his stuff to WikiLeaks and it had all gone public. The public would have known *less* (the story would have died more quickly) and the US national security would actually have been hurt (rather than just its image as happened).