President Obama delivered a speech on Friday outlining his plans to address the widespread outrage over the domestic surveillance activities of the National Security Agency. However well-intentioned, the president’s proposals indicate he just doesn’t get the constitutional notion of delegated powers.
Implicit in the Fourth Amendment is the principle that the government should remain powerless unless and until an individual is reasonably suspected of having committed a crime. It isn’t even allowed to search one’s person or papers (viz. phone records, emails) to collect the proof it needs until it persuades a judge that it has probable cause.
The only reason the Fourth Amendment offers any protection is it prescribes an adversarial process. The judicial branch is predisposed to refuse to issue a warrant until the executive branch provides sufficient evidence of probable cause.