Tadayoshi Kohno
Security researcher who showed that voting machines, pacemakers and cars were all computers — with everything that implies.
As a grad student in 2003–04, Kohno was lead author of the analysis of Diebold's voting machine code with Avi Rubin, exposing hard-coded keys and the ability to vote more than once. At the University of Washington he was part of the 2008 study that wirelessly disabled an implantable defibrillator, and in 2010, with Stefan Savage's group, showed that an ordinary car could be taken over via its CAN bus — five years before the far more publicised Jeep hack.
On the cryptographic side he designed CWC mode with John Kelsey and Doug Whiting and described the herding attack on hash functions. The common thread: find the things nobody thought of as computers before someone else does.