Reply #20: Because it would be unprofessional

[Muddleoftheroad]

And would put their profession and fellow journalists in jeopardy.

Journalists don't reveal sources so that:

* Rotten people can come forward and don't feel journalists will rat on them. If they feel they will, they will get rid of the threat.
* Good people can come forward and journalists will protect them.
* So that the profession is protected as the Fourth Estate -- the fourth branch of government.