“Basically, if the password is a physical thing she has, than the Fifth Amendment does not protect it. But if the password is deemed to be something the defendant knows, it is protected.” — From John Fontana of ZDNet quoted by David Sirota in Salon.com commenting on a criminal prosecution in Denver
The password is information. Therefore it is not a physical thing because information is not a physical thing. Instances of information occur on or in physical things. The physical things on or in which information occurs are of course physical things. So if she had written the password on a piece of paper and she still possesses that piece of paper with the password written on it, then, by the quote, the 5th amendment does not protect that piece of paper from being handed over. But if the password is not stored in, or recorded on, any physical substrate but her brain, then, by the quote, the 5th amendment protects it.
Information is not a physical thing.
The password as information can exist on or in many substrates at many different places and at many different times. The instances of the password as information can come and go like a wave in water: electric or magnetic charges in a computer, tiny dots on a CD or DVD disk, pencil smudges on a piece of paper, or ink on paper, or some patterns in her brain, or sound waves in the air if she should speak the password out loud in a courtroom. The connections between all these — what makes them all instances of the same information (namely her password) — is that these various patterns on all their variable substrates are convertible from one to another by specific more or less known processes. For example she knows how to speak the password out loud. That is she can convert the password pattern in her brain into sound waves via speaking. The sound waves travelling through the air to another person (who understands her language) will be converted to a pattern in the hearer’s brain that will be another instance of her password information, assuming it was heard and understood correctly. The patterns in her brain and in the hearers brains will not be identical. At best they will be similar. Same for two instances of her password written on two pieces of paper. They may be similar. They will not be identical.
Her password is not a physical thing she has. There are instances of it from time to time somehow recorded as various patterns of neuronal activations in her brain. Rather it is a collection of instances here and there, and at various times, with some instances in her brain and some instances outside her brain. Note that when the password is spoken that instance of the password as a pattern of sound waves in the air between the speaker and the hearer exists only for a second or so whereas if the password had been stamped on a bar of gold in some bank vault, that instance might last for hundreds of years. The collection extends over space and time. The collection is not attached to any point in space or any point in time. The collection may have physical things in it from time to time, but the collection is not a physical thing.
(This post may not seem to be connected with How to Make a Revolution, but this example gives a good opportunity to talk about the nature of information — what information is. And since my emphasis is on how information spreads through cultures, this is relevant.)