The reason Googlers get really ticked off about leaks is that they ruined the very candid and open internal culture we used to have. In the 10 years I've been there I've seen us go from TGIF sessions where Larry and Sergey and Eric openly discussed things that every other employer I'd had before would have kept quiet ... to the situation now which is a lot less like that. And it has a lot to do with leaks from those very TGIFs.
Now I certainly wouldn't be talking about "punching people" or "wanting them dead"... But I am not happy when my coworkers violate trust by leaking. Unless we're talking about gross ethics violations, harassment, etc. leaking internal stuff doesn't improve anything for anybody except maybe the ego of the leaker.