Orin Kerr in The Volokh Conspiracy:

In this post, the third in a series, I want to discuss what I think is the policy question at the heart of the Apple case about opening the San Bernardino iPhone. The question is, what is the optimal amount of physical box security? It’s a question we’ve never asked before because we haven’t lived in a world where a lot of physical box security was possible. Computers and cellphones change that, raising for the first time the question of how much security is ideal.