At the risk of contributing to one of Edna's non-sequiturs, I respond as follows:
I am completely ignorant of a journalist's ethical duties with respect to his sources, but suspect such duties are fleeting. I think if their are circumstances upon which an attorney can reveal confidential client information, there probably are circumstances when a journalist can be compelled to produce sources (e.g., prevent a homicide or battery).
If it's important enough to prejudice a client, it's important enough to obtain from a dipshit journalist.