Should it be encouraged/discouraged? Lawful/unlawful? Acceptable under certain conditions? etc...
[url=http://en.wikipedia.org/wiki/Whistleblower]Here's the wiki[/url] about it if you're unsure what it is.
It's just my opinion that whistleblowing is never "betrayal." They are the ones that are maintaining a moral compass, not the corporation or individual that is committing fraud, etc. When I commit to working for a company, I am not signing a binding contract that says I am adopting the corporations moral compass; I should feel no shame calling attention to amoral activities that I witness.