The FBI is basing the application of the 1917 law on judgments made during the last 90 years.
There have been many advances in communication over that time. As a matter of fact, five years is a lifetime in the advances in electronic communications. Don't you think the FBI should also change with the advances in communication technology?
A question I would like to hear asked is, "If Congress had passed in 2008 exactly the law passed in 1917, would Comey enforce that law or ignore it? How many years must pass in order for the intent of Congress to mean nothing?