Michael Berry and I analyze the implications of United States v. Rosen in this NRO column. Here's the introduction:

Can journalists be prosecuted for knowingly reporting classified information related to the War on Terror? What about Washington lobbyists who pass on secret information concerning defense matters or foreign affairs? Some would be inclined to say that except in the most exceptional circumstances such communications are protected by the First Amendment, but a recent decision by a federal court in Virginia seems to conclude otherwise. The decision sends a clear warning to reporters who cover the war on terrorism, as well as scholars, think-tank analysts, and lobbyists who study, write, and advocate about issues bearing on the national security. Read broadly, the decision could sanction federal prosecution of anyone who willfully communicates classified national defense information to the public. Fortunately, the decision also contains limiting language that provides some safeguard for First Amendment values and makes it more difficult for federal prosecutors to convict potential defendants engaged in constitutionally protected activity, journalists and non-journalists alike.