  Research on optical TEMPEST has moved forward since 2002 when the first pair
of papers on the subject emerged independently and from widely separated
locations in the world within a week of each other. Since that time,
vulnerabilities have evolved along with systems, and several new threat vectors
have consequently appeared. Although the supply chain ecosystem of Ethernet has
reduced the vulnerability of billions of devices through use of standardised
PHY solutions, other recent trends including the Internet of Things (IoT) in
both industrial settings and the general population, High Frequency Trading
(HFT) in the financial sector, the European General Data Protection Regulation
(GDPR), and inexpensive drones have made it relevant again for consideration in
the design of new products for privacy. One of the general principles of
security is that vulnerabilities, once fixed, sometimes do not stay that way.
