Over at Balkinization, Marty Lederman has a post arguing that the recently-discovered monitoring of satellite phones in the Middle East violated the Fourth Amendment:

The leading — indeed, virtually the only — case on the question indicates that the E.O. 12333 requirement that the U.S.-person target of such overseas surveillance be an agent of a foreign power, is also a Fourth Amendment minimum. That court held that such surveillance of U.S. persons overseas can be done without a warrant only (i) when authorized by the President or the Attorney General; (ii) when conducted primarily for foreign intelligence purposes; and (iii) when targeted at foreign powers or their agents, including American citizens believed to be agents of a foreign power. See U.S. v. bin Laden, 126 F. Supp. 2d 264, 277 (S.D.N.Y. 2000).

Assuming that some or all of that holding is correct, then the NSA activity described by ABC News would appear to violate the Fourth Amendment, too, even if it did not violate FISA.

  I think Marty is wrong, and that the monitoring probably did not violate the Fourth Amendment even if you accept the bin Laden case.

  (1) First, it appears from news reports that most of the monitoring was of members of the military using military-provided phones, and that users were notified that the phones would be monitored. This monitoring was clearly constitutional, as the notice waived an expectation of privacy under O'Connor v. Ortega and no warrant would be required under Title III, a precondition to FISA's warrant requirement.

  (2) Second, monitoring of individuals who were not U.S. citizens, permanent residents, or otherwise had strong connections to the U.S. would not implicate the Fourth Amendment under United States v. Verdugo-Urquidez.

  (3) Ok, but what about any U.S. citizens who were monitored abroad who were not in the military and not agents of a foreign power? At this point, it's important to keep in mind that the monitoring was of satellite phones, phones that work by broadcasting signals directly to communications satellites. There are no cases on how the Fourth Amendment applies to monitoring of satellite phones, but there are a bunch on how the Fourth Amendment applies to cordless phones. Here's what I wrote on the issue in my computer crime casebook:

  In the 1980s, telephone companies began selling cordless telephones to consumers. Cordless telephones work by broadcasting FM radio signals between the base of the phone and the handset. Each phone has two radio transmitters that work at the same time: the base transmits the incoming call to the handset, and the handset transmits the outgoing call to the base. Before the mid-1990s, cordless phones generally used analog FM signals that were easy to intercept. Government agents would occasionally listen in on the cordless telephone calls of suspects without a warrant by intercepting the signals using widely available FM radio scanners. In your view, should such surveillance be prohibited by Katz v. United States or permitted by Smith v. Maryland?
  Courts relied on Smith v. Maryland to reject claims of Fourth Amendment protection in the contents of such cordless telephone calls. Because cordless phone intercepting devices merely pick up a signal that has been "broadcast over the radio waves to all who wish to overhear," the interception was held not to violate any reasonable expectation of privacy. McKamey v. Roach, 55 F.3d 1236, 1239-40 (6th Cir. 1995). See also Tyler v. Berodt, 877 F.2d 705, 707 (8th Cir. 1989); Price v. Turner, 260 F.3d 1144, 1149 (9th Cir. 2001). Courts reached the same result when the suspect was using a traditional landline telephone, and happened to be engaged in conversation with someone who was using a cordless phone. See United States v. McNulty, 47 F.3d 100, 104-106 (4th Cir. 1995).

  Although there are no cases on it, I think there's a decent argument that the same argument would apply to satellite phones. There are arguments against, to be sure — arguments that I am certain commenters will make in the comment threads. But the reasoning of those cases is pretty broad.

  Anyway, for those reasons I think the monitoring here probably didn't violate the Fourth Amendment, even if we accept Judge Sand's opinion in the bin Laden case.

UPDATE: Marty responds here.