Now that Defense Department officials are expressing concerns about FBI and administration efforts to force Apple to provide a "back door" to its iPhone encryption, and even the Obama crew is hesitant to ask for Congressional action to force Apple's hand (probably because Congress would be likely to go overboard in the ecstasy of patriotic orgasm), it's time to reconsider just what "vital information" might be available on the phone in question.
We should bear in mind that the phone's metadata has been examined, and Farook did not use it to contact anybody outside the United States. The FBI knows who was in communication with the San Bernadino attacker, and presumably is thoroughly investigating those persons. If there is any significant reason to suspect that any of them was involved, surely warrants could be obtained to search their phones. Since they're not dead, their passwords are not lost; and given the propensity of individuals to give up their civil rights to "prove their innocence," Farook's communications could be read without penetrating his iPhone's encryption.
Face it: law enforcement just can't tolerate any restrictions on its ability to invade our privacy. Fourth Amendment rights have been weakened enough already. It's time to draw the line.