Once we impose those standards on the military and intelligence agencies, however, we are either guaranteeing failure or we must accept a certain level of error. If the military and intelligence agencies had to follow law-enforcement standards, their mission would fail because they would not give us any improvement over what the FBI could achieve anyway. If the intelligence community is to detect future terrorist attacks through analyzing electronic communications, we are asking them to search through a vast sea of e-mails and phone-call patterns to find those few which, on the surface, look innocent but are actually covert terrorist messages. If we give them broader authority, we would have to accept a level of error that is inherent in any human activity. No intelligence agency could perform its mission of protecting the nation’s security without making a few of these kinds of mistakes. The question is whether there are too many, not whether there will be any at all.