The U.S. Supreme Court has just blocked a lawsuit over the federal government's sweeping electronic monitoring of foreigners suspected of terrorism or spying.

The 5-4 conservative majority on Tuesday morning concluded that the plaintiffs - a group of attorneys, journalists and others - lacked "standing" or jurisdiction to proceed, without a specific showing they have been monitored. The National Security Agency has in turn refused to disclose monitoring specifics, which detractors call "Catch-22" logic.