Eugene Volokh writes:
Over the last several years, various courts have held — in cases such as Dendrite Int’l, Inc. v. Doe No. 3 and Doe v. Cahill — that the First Amendment provides substantial, though limited, protection against subpoenas aimed at unmasking anonymous commenters; for more details on that protection, see this EFF analysis. But last week, Doe v. United States (N.D. Cal. Oct. 4, 2011) held that such rules generally do not apply to government investigations, here by the SEC, as opposed to investigations by private litigants. I just thought this was worth noting for readers who follow such matters.