He has been involved in investigating and countering computer crimes going back to the late-1990s. Dave was first to describe DDoS attack tools in 1999, did early researcher into bots and botnets, including P2P for botnet command & control. Dave has pushed the limits, but tries to do it in a way that is ethically defensible. He has written extensively on ethics, first speaking publicly about the 'Active Response Continuum' at AusCERT 2005. He serves on one of the UW's Institutional Review Boards evaluating human subjects research, and co-edited 'The Menlo Report: Ethical Principles Guiding Information and Communication Technology Research' and 'Applying Ethical Principles to Information and Communication Technology Research: A Companion to the Department of Homeland Security Menlo Report.'