Typically, a media entity cannot be compelled to reveal a source. There are exceptions, but none that would likely apply in the Walsh case. The reason that newspapers do not reveal their sources and fight hard to protect them is so that they can give assurances to other confidential sources in the future. The protection that the media gives a source is basically contractual. Bob Woodward tells deep throat -- if you talk to me and let me use your information, I will never reveal your identity. These contracts are basicaly considered sacrosanct as a matter of journalistic ethics, and for good reason. However, all this goes out the window if a confidential source publicly denies that he was the source. At that point, the newspaper is, under well established jouranlistic standards and rules, entirely free to come forward and say, "oh yes you were." And they can play hardball -- they can defend themselves by showing reporters notes, transcripts, editors notes, or even tapes of the conversations. Walsh has now publicly denied that he was the Herald's source. As far as I know, the Herald has not contradicted that report. There really is only one implication if the Herald continues to refuse to contradict Walsh: That Walsh was NOT the Herald's source. This could mean (1) the Herald didn't have a source, or (2) it could mean that they had a different source. Number 1 is obviously bad and would expose them to considerable liability. Number 2 would not and would probably insulate them from liability, but raises a host of other questions -- who was their source? If it was someone claiming to know Walsh and giving second hand information -- my guess actually -- they really are scumbags with absolutely zero journalistic integrity.