[fauxfauxpas]

somewhat related - excerpt from Cryptonomicon - The percussionist stands up. "Every radio operator has a distinctive style of keying—we call it his fist. With a bit of practice, our Y Service people can recognize different German operators by their fists—we can tell when one of them has been transferred to a different unit, for example."

and this article by Schneier - Identifying People By Their Writing Style - https://www.schneier.com/blog/archives/2011/08/identifying_p...