Twitter continues to roll out anti-harassment measures.

Twitter is implementing tools that can automatically identify patterns in the way harmful tweets are made and distributed. If it identifies a harmful account, it will truncate the user’s visibility.

For instance, if a user routinely replies to accounts that don’t follow it, or repeatedly violates Twitter’s rules, Twitter might make it so that the tweets are invisible to everyone except the user’s followers for a set amount of time. Twitter users who have already experienced this in tests are calling it “Twitter jail.”

Source: Twitter rolls out more anti-harassment measures — like automating Twitter jail – Mar. 1, 2017