The US Court of Appeals case
document (83-page .pdf file) gets to the heart of the matter.
The following excerpt is from the concurring opinion from Circuit Judge Sentelle..
Last there be any mistake to the breath of the rejection of the claimed First Amendment privilege, the High Court went on to recognize that "there remain those situations where a source is not engaged in criminal conduct but has information suggestion illegal conduct by others." As to this category of informants, the Court was equally adamant in rejecting the claim of First Amendment privilege:
[W]e cannot accept the argument that the public interest in possible future news about crime from undisclosed, unverified sources must take precedence over the public interest in pursuing and prosecuting those crimes reported to the press by informants and in thus deterring the commission of such crimes in the future."
Judge Tatel quotes from Garland v. Torre:
"Freedom of the press, hard-won over the centuries by men of courage, is basic to a free society. But basic too are courts of justice, armed with the power to discover truth. The concept that it is the duty of a witness to testify in a court of law has roots fully as deep in our history as does the guarantee of a free press."
Tatel later writes an interesting tidbit on state vs. federal law and the uncertain role of bloggers:
As the Jaffee dissent pointed out, a far greater proportion of states--indeed, every state--established the psychotherapist privelege by statute, yet the majority considered that fact 'of no consequence.' Nor does it matter that unconventional forms of journalism--freelance writers and internet 'bloggers,' for example--may raise definitional conundrums down the road.
Further on:
Just as attorney-client communications "made for the purpose of getting advice for the commission of a fraud or crime" serve no public interest and receive no privilege, neither should courts protect sources whose leaks harm national security while providing minimal benefit to public debate.
To conclude:
It thus makes no difference how these reporters how these reporters responded to the information they received, any more than it matters whether an attorney drops a client who seeks criminal advice (communication subject to the crime-fraud exception) or a psychotherapist seeks to dissuade homicidal plans revealed during counseling (information Jaffee suggested would not be priveleged. In all such cases, because the communication is unworthy of protection, recipients' reactions are irrelevant to whether thei testimony may be compelled in an investigation of the source.