I work in the industry (QA consultant for a large company - we may or may not have been under scrupule recently DUE to a leak from one of our testers regarding a videogame). And you're damn right it aggravates me - people who do that at my place of work are often shunned, and when I hear of leaks from a project that I know is in-house, I can't help but to think maybe it's one of us and it makes me want to straight up rampage.
Wow, the internal conflicts that could have arose during that must have been insane. I could't imagine how upset various employees must get during a leak. Personally I feel bad (not that bad, but still bad) for Nintendo for going through the trouble to make their Nintendo Direct announcement and then to have a leak go through just a day ahead of time. If you don't mind me asking, what company or game would that have been? Was it a recent leak? (no worries if you'd rather keep that quiet).
I'd rather keep that quiet indeed - I can't speak too precisely of that I do seeing I am under a NDA.