An interesting legal battle is ongoing over whether a person can be forced to reveal a computer password, or whether she is protected from doing so by the Fifth Amendment’s protection against self-incrimination.
Under existing case law, the latter position seems stronger to me. The controlling case seems to be Doe v. United States. At issue in Doe was whether someone could be forced to sign a consent directive allowing foreign banks to disclose some information the government wanted. The court’s opinion wrote:
We do not disagree with the dissent that “[t]he expression of the contents of an individual’s mind” is testimonial communication for purposes of the Fifth Amendment. . . We simply disagree with the dissent’s conclusion that the execution of the consent directive at issue here forced petitioner to express the contents of his mind. In our view, such compulsion is more like “be[ing] forced to surrender a key to a strongbox containing incriminating documents,” than it is like “be[ing] compelled to reveal the combination to [petitioner’s] wall safe.”
The analogy to a safe’s combination came from the dissent, which said:
A defendant can be compelled to produce material evidence that is incriminating. . .But can he be compelled to use his mind to assist the prosecution in convicting him of a crime? I think not. He may in some cases be forced to surrender a key to a strongbox containing incriminating documents, but I do not believe he can be compelled to reveal the combination to his wall safe — by word or deed.
So the question is whether a password is material evidence like a strongbox key, or the contents of a mind like a safe’s combination. I think it’s clearly the latter.