The problem at the First Amendment Moot Court Competition this year dealt with newsman's privilege, or the ability of a journalist to refuse to divulge his source.
This was an interesting problem because it confronts whether there is a newsman's privilege at all, and if so, to what extent it might be limited.
Now, there is a newsman's privilege when there is a specific law saying that there is. Many states (I forget the count, but I think it's around 31) have some sort of shield law on the books that articulates whether and how a journalist can refuse to identify a source they promised anonymity to. The problem is that in the instances when there's no applicable law written in a statute it's up to the courts to decide whether a common law privilege can be inferred from the First Amendment. Our current state of confusion is that different courts have decided the answer to that question differently.
There is only one Supreme Court case directly on point: Branzburg v. Hayes, 408 U.S. 665 (1972). That case was actually three cases combined into one result, and all involved reporters being compelled to testify before a grand jury and reveal information they had promised their sources they wouldn't. The Court affirmed that they had to testify, and, moreover, seemed to also say that there was no newsman's privilege provided for by the First Amendment at all. Or at the very least, there was none available for a journalist called to testify before a grand jury.
However, there's some confusion as to whether that's what the Court really said. The confusion mostly stems from Justice Powell's concurrence, which, though it agreed with the holding that these particular journalists needed to testify, seemed to also limit the scope of the decision's holding. Courts have since grappled with whether his concurrence did in fact truly limit its scope, which would lead to a different result: rather than there never being a privilege for reporters before a grand jury, there could be a qualified privilege that sometimes could compel a journalist to testify (and therefore sometimes not).
There are two other questions left unsettled by this case as well. One, whether the Branzburg holding can be limited to its facts, and two, whether Federal Rule of Evidence 501 changes may have also limited its applicability. At the competition the 501 scenario was only minimally explored. But it could be relevant to a journalist looking to assert privilege, in that after the Court ruled in Branzburg, Congress codified testimonial privileges. But only somewhat: Rule 501 does not explicitly allow for a newsman's privilege, though at the same time it doesn't preclude it. The language is actually fairly confusing, unhelpfully lending even more confusion to an already confused issue. But to the extent that it opens a door for a privilege, it did so subsequent to the Branzburg ruling, and thus the Branzburg precedent needs to be reconsidered in light of it, as the Congressional law may have overridden its holding.
With regard to the whether Branzburg can be isolated to its facts, in all the cases covered by that decision the reporter had personally witnessed (at least potentially) criminal behavior and was then called to testify before a grand jury about what they had directly observed. Still, the policy interests in compelling any person - even a journalist - to testify about a crime they personally witnessed are much stronger than those in compelling a reporter to disclose what he may have learned about a crime after the fact during the course of his investigation, and only by virtue of that investigation. In fact, the policy interests in investigating and prosecuting crime are perhaps better served by NOT compelling disclosure in the latter situation, especially if it is only because of the promise of anonymity by reporter to the source that some crimes even come to light in the first place. The problem with a per se rule, that whenever a journalist is called before a grand jury he MUST testify, is that no source with information about a crime who wishes to remain anonymous will ever be able to speak to a reporter, since to allege a crime will likely result in an investigation, and the investigation will result in the automatic disclosure of his identity.
There is also the question of whether there might be a newsman's privilege in other types of judicial circumstances, like civil cases. In these situations lower courts have generally allowed for reporters to refuse to disclose their sources, essentially evaluating the question on a case-by-case basis. For instance, in some libel cases, when the journalist's refusal to testify would extinguish the libel claim, courts have sometimes compelled the journalist to testify. But in other cases, when the civil litigant would merely be aided in having access to the journalist's information but was otherwise not dependent on it, or when that dependency would still not outweigh the First Amendment interests in journalists being able to protect their sources, the journalist's disclosure was not compelled.
The problem with compelling journalists to disclose their sources is that doing so may undermine the First Amendment. The First Amendment guarantees a free press, which means that the press is free to publish what it will without hindrance by the government. But when the government takes action that affects the press's ability to gather the information it wants, it necessarily inhibits its ability to publish what it wants.
By not allowing journalists to maintain promises of anonymity to their sources it limits their access to information. There are many sources who will not give information to the press without the protection of anonymity. If that protection is unavailable, their secrets will remain with them. Thus the utility and value of having an independent press is lessened, as its universe of what it can report on is also lessened.
All that said, a remaining issue of contention is, assuming there is a newsman's privilege of some sort, who can claim it. The issue raises significant questions of "who is a journalist." The hazard of allowing it to be too broad is that it could inadvertently create a special class of people, who unlike normal people, are not subject to the typical duties to testify. On the other hand, the privilege could be narrowed by tying it to the activity. If the reporter has gained information through a typically journalistic activity - gathering information for the purpose of disseminating it to the public - then that could provide the courts with some guidance for whom to permit to assert it. Just as a professional newsperson would not be able to assert a testimonial privilege on a private matter unrelated to the scope of his work, instead tying his privilege only to the practice of his craft, the newsman's privilege could be limited to those who, at the time they acquired the information, were themselves practicing that craft - whether professionally or not.