Incitement to terrorism connects the dots between evil words and evil deeds. Hate precedes terror. History has already taught us that incitement to genocide and to crimes against humanity unchecked will inevitably bring devastation to humankind. Incitement is an affront to the dignity of its victims, and poses a dire threat to all people of good will. However, combating incitement to terrorism poses operational, constitutional and human rights challenges on many fronts, both domestically and internationally. What is incitement? Where should the line be drawn between protected speech and incitement that should be criminalized? Does war change the calculus of what are appropriate and lawful measures to contain and respond to such incitement? And, perhaps most challenging of all, how does social media and the nature of communication and engagement in today's virtual world change or complicate how we think about and can respond to incitement?