1. Blocking or banning a user or group from a service or online platform due to their use of hate speech (or violating the platform's terms of service, etc.)
   "The social media company engaged in deplatforming of accounts that repeatedly spread misinformation";
   - no-platforming
    
2. Political activism with the goal of excluding or shutting down offensive or controversial speakers or speech
   "Students engaged in deplatforming efforts to prevent a controversial figure from speaking on campus";
   - no-platforming

1. Block someone's ability to contribute post a debate or (esp. online) platform, e.g. because of use of hate speech, inciting violence, violation of terms of service, etc.
   "The social media company deplatformed the user for repeatedly spreading misinformation"

Encyclopedia: Deplatforming