More on Pass Phrases and Fingerprints .... Gestures

Yesterday I posted a short blog on an interesting VA decision regarding the application the Fifth Amendment privilege to the question of unlocking cell phones and other devices.  The short summary is that the court held that compelling disclosure of a pass phrase or code was protected and could not be compelled, but that the use of a fingerprint to unlock the phone could be compelled since a finger was not testimonial.  Two updates: First, I am happy (HT: Dan Terzian) to be able to share with you the text of the court's opinion -- which comes in the form of a letter opinion from the presiding judge. Second, I want to share an interesting question (HT: Ray Setzer) that ought to have occurred to me, but did not:  What about a gesture?  For example, I have an Android OS and I unlock my tablet not through a numeric pass code or through a fingerprint but, instead, by using gestures to draw a pattern on the tablet.  So ... can I be compelled to make that gesture? Is the gesture like a pass phrase -- that is a compelled testimonial thought protected by the Fifth Amendment privilege?  Or is it a physical expression (more like a person's gait or voice exemplar) that is not privileged? It's a great chestnut question (almost perfect for an exam in law school).  My own instinct/guess is that gestures will be seen as requiring thought and testimony and that they are therefore protected.  But I don't have a very high degree of confidence in that instinct ....