The story of Tay marks an interesting development in the field of artificial intelligence, but to those dealing with Holocaust and genocide denial, it carries a more ominous and almost symbolic note: it is the reflection of a problem with which they are well acquainted. The denialism has been explored in a great range of contexts which show variations both regarding their geographical distribution and regarding the events whose memory deniers target. Denial – and the reactions by individual States and the international community – has thus been discussed in relation to the Holocaust and the atrocities committed against the Armenians, the Soviet Gulag system, and genocide in Bosnia and in Rwanda. The divergence of the existing situations highlights the fact that denial, under certain circumstances, can have consequences that reach far beyond the direct discriminatory effects of hate speech.