The court also holds that the program violates the First Amendment, because it deters some people from communicating with the plaintiffs, given the risk that the communications will be overheard. Note, though, that this judgment rests entirely on the court's earlier conclusion (which is in my view not fully defended) that the eavesdropping violates the Fourth Amendment.

All publicly known eavesdropping -- or for that matter the prospect of possible searches of tangible papers -- poses the risk that some communications will be deterred. Eavesdropping conducted pursuant to properly issued warrants (ones that can be based on mere probable cause, rather than any solid proof that the eavesdropping will yield incriminating evidence) poses that risk. Eavesdropping conducted purusant to properly issued FISA orders, which don't even require probable cause that the speech collected will be incriminating (only probable cause that the targeted person is an agent of a foreign power), poses that risk. Constitutionally permissible border searches of papers pose that risk.

But there's no need to show in any of these cases (as the court in this case suggested) that the search is based on "a compelling governmental interest; and that the means chosen to further that interest are the least restrictive of freedom of belief and association that could be chosen." At most, the Fourth Amendment rules (which generally require only a warrant and probable cause and not a compelling interest and narrow tailoring, sometimes don't even require a warrant, and sometimes don't even require either a warrant or probable cause) are made somewhat more demanding by the First Amendment (see, e.g., Lo-Ji Sales, Inc. v. New York), though even that doctrine is quite limited. And in a case like this one, I know of no Supreme Court cases suggesting that a search that's valid under the standard Fourth Amendment rules would violate the First Amendment.

So the court's First Amendment conclusion, if it's correct, would be correct only if the court is right to say that the program violates the Fourth Amendment, and that a violation of the Fourth Amendment in such a situation yields a violation of the First Amendment. Perhaps the court is correct here, but it's important to recognize that the First Amendment holding is derivative of the Fourth Amendment holding, rather than being a fully independent basis for the decision.