Harassment: You may not incite or engage in the targeted abuse or harassment of others. Some of the factors that we may consider when evaluating abusive behavior include:
- if a primary purpose of the reported account is to harass or send abusive messages to others;
- if the reported behavior is one-sided or includes threats;
- if the reported account is inciting others to harass another account; and
- if the reported account is sending harassing messages to an account from multiple accounts.
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.
An opinion translated to action, though -- here in the form of Tweets -- is not merely an opinion.
Twitter has a thing called "The Twitter Rules" which includes a section on "Abusive Behavior". https://support.twitter.com/articles/18311
Here's some of Twitter's relevant rules:
Harassment: You may not incite or engage in the targeted abuse or harassment of others. Some of the factors that we may consider when evaluating abusive behavior include:
- if a primary purpose of the reported account is to harass or send abusive messages to others;
- if the reported behavior is one-sided or includes threats;
- if the reported account is inciting others to harass another account; and
- if the reported account is sending harassing messages to an account from multiple accounts.
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.