Twitter Automation Rules, regarding bots, botnets – updated Nov. 3, 2017.

Trending topics: You may not automatically post about trending topics on Twitter, or use automation to attempt to influence or manipulate trending topics.”

Multiple posts/accounts: You may not post duplicative or substantially similar Tweets on one account or over multiple accounts you operate.

… “Abusive behavior: You may not engage in any automated activity that encourages, promotes, or incites abuse, violence, hateful conduct, or harassment, on or off Twitter.”