In the spectrum of crimes involving the leaking of classified information, publicly revealing the contents of SIGINT — signals intelligence — is one of the most serious felonies. Journalists (and all other nongovernmental citizens) can be prosecuted under federal law for disclosing classified information only under the narrowest circumstances; reflecting how serious SIGINT is considered to be, one of those circumstances includes leaking the contents of intercepted communications, as defined this way by
18 § 798 of the U.S. Code:
Whoever knowingly and willfully communicates … or otherwise makes available to an unauthorized person, or publishes … any classified information … obtained by the processes of communication intelligence from the communications of any foreign government … shall be fined under this title or imprisoned not more than ten years, or both.