Spot-on analysis of what has gone on: journalistic responsibility doesn't apply to this hack -- they haven't stumbled across details of shady dealings or bad treatment of users.
Instead, it seems TechCrunch want to publish the info because a) they find it mildly interesting, and b) a voyeuristic 'scoop' on Twitter is guaranteed to generate a lot of traffic.
If they consider themselves a "news organization" then they have an obligation to their readers to publish "news". I don't know how much of the documents they're gonna publish (3 of 400?), but hopefully they'll have reasonable judgement; ie. plans for a Twitter tv show is newsworthy (tell me that wouldn't end up on HN), and disclosing private details of an employee is not.
All these docs are gonna be leaked at some point, then everyone will be "reporting" on it.
"Other people will report sensitive info" isn't ethical justification.
IMO TechCrunch should have gone down the honest route of 'It's interesting, and news-worthy, and we won't publish anything damaging' in their response instead of bringing in this 'journalistic responsibility' spiel.
Instead, it seems TechCrunch want to publish the info because a) they find it mildly interesting, and b) a voyeuristic 'scoop' on Twitter is guaranteed to generate a lot of traffic.