To quote this column:
Protecting confidential sources has been a sacred ethical precept in publishing ever since John Twyn was arrested in 1663 for printing a book that offended the king. Twyn refused to reveal the name of the book’s author, so he was publicly castrated and disemboweled, and his limbs severed from his body. Each piece of his body was nailed to a London gate or bridge.
So, on the bright side, we have evidently progressed.
Though, as you’ll see reading that column, we haven’t progressed much. There are several cases where journalists are getting thrown in jail (or very close to it) for not revealing their confidential sources, and it’s starting to get messy.
Would I reveal a confidential source? If the story is worth it, no way. There are so many organizations out there (SPJ, for example) that would fight their butt off for you and make a spectacle out of the government that it’d be worth it to not give that information up. You’d also burn any sort of confidence you had with that source, killing off the possibility if getting information from them in the future. Most of the time, confidential sources are ones that don’t want to go on the record because of reasons out of their control — like they’d lose their job, for instance — and you don’t want to do that to a source.
Thanks Barney for the link.