When I blew this whistle on Google, I pissed off a lot of engineers even though I never had a problem with them. And, in that case, it didn't really hurt them at all because a single whistleblower can't take out Google. The worst it has to fear is mild embarrassment.

The lesson I learned is that whistleblowing often angers the wrong people. In a better world, only wrongdoers would suffer, but that doesn't seem to be the world that exists. Google's horrible management is still horrible; its otherwise disinterested engineers (who I'd be inclined to like) seem to be the ones upset about it. Which might suggest that it wasn't the right course of action, since the wrong people feel attacked while the deserving targets don't seem to have changed.

If I blew a whistle on this startup, I'd probably end it (unlike Google, on which I had no real effect). Unfortunately, it'd be engineers who'd suffer (losing jobs, when the company folds) but management would be OK. That's the problem. The good guys are more vulnerable to that sort of thing than the genuine malefactors. The CEO's independently wealthy and has flat-out said he doesn't care if that startup fails (since the investors took it away from his original vision-- to something much better than what he started with). If I blew a whistle on him, I'd just take that firm off his books and he'd move on to some other project.

Now, if they have a huge success, then that changes. In that case, engineers get their payoff no matter what I do, but managers risk personal embarrassment (as they deserve, because that company's whole management team is unethical). So, then it might make sense to divulge. Right now, though, I'm just nervous that it would hurt the wrong people.