Jabara v. Kelley, 476 F. Supp. 561 (ED Mich. 1979), vacated & remanded sub nom. Jabara v. Webster, 691 F.2d 272 (6th Cir. 1982), cert. denied, 464 U.S. 863 (1983). SCOTUS only reviewed a request to be released from custody, and did not touch the questions relating to the fourth amendment.
In 476 F. Supp. 561 (ED Mich. 1979), the court found the NSA/FBI warrantless examination of the contents of Jabara's communications to violate Jabara's fourth amendment rights.
I do agree with your larger point, that acts of Congress cannot limit executive power granted under the Constitution; nor can acts of Congress limit the rights of the people beyond what is expressed by the Constitution.
There has been no offical confirmation anyhere that NSA was listening to the contents of anyone's communications in this particular operation.
I am of the opinion - nothing more - that they were capturing the connections between known and (previously) unknown individuals for the purpose of building a network diagram of al Qaeda operators and sympathizers, whether internationally or here in the US.
Also that FISA warrants were subsequently requested against individuals found to have any communication patterns of note.
This approach would be permissable under Jabara.
Nope. Jabara came in under the 'agent of a foreign power' exception.