From proff's strobe to modern day distributed network scanners, probing remote systems and applications to assess a system's security posture is a core part of our offensive and defensive tool kits. This panel discussion will examine the state of the art of network and application scanning. During the session, the entire Internet will be scanned at least once by the panelists--maybe even a few times. We will discuss the results of a recent scan of large scale cloud providers and the issues the scan uncovered. The panel will also examine new tools utilizing application scan results to enable real-time defenses against compromised or weak systems. Finally, the panelists will engage in a discussion on the ethics of network scanning, especially as it pertains to the modern capability of large scale, nearly instantaneous scanning of the entire Internet.