Twitter has launched new rules against hate speech that could see many people banned for life.
The restrictions, which were announced a month ago, but took effect on December 18, prohibit users from threatening or promoting violence against others "on the basis of their group characteristics".
Users are also not allowed to post violent threats or statements that wish "serious physical harm" on others, or to affiliate themselves with organisations that promote violence.
The new restrictions are an attempt to combat the rise of hate speech against minority groups on the site.
Extremist voices, such as far-right UK group Britain First, have used Twitter to promote bigotry, by posting misleading videos about Muslims.
In what has become known as "The Purge", anyone who violates the site's new policies could find themselves permanently banned.
But some are concerned that this could mean people with certain ideologies could be forced off the site unfairly.
Some have suggested that, according to Twitter policy, US President Donald Trump should be banned.
Others took issue with some of the exceptions to the restrictions.