Twitter Rules
Hateful conduct: You may not promote violence against or directly attack or threaten other people on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or disease. We also do not allow accounts whose primary purpose is inciting harm towards others on the basis of these categories.
Examples of what we do not tolerate includes, but is not limited to behavior that harasses individuals or groups of people with:
violent threats;
wishes for the physical harm, death, or disease of individuals or groups;
references to mass murder, violent events, or specific means of violence in which/with which such groups have been the primary targets or victims;
behavior that incites fear about a protected group
Seems pretty clear cut to me, his account should be suspended.
