To build a positive environment for contributors and manage the community around your project, you can block and unblock a user from your personal account and lock conversations within issues and pull requests.
You can temporarily restrict certain users from commenting, opening issues, or creating pull requests in your public repository to enforce a period of limited activity.
You can block a user to deny them access to your activity and repositories, and to prevent them from sending you notifications.
You can view a list of all users you've blocked from your personal account.
If you've mended fences with a GitHub user you've blocked, you can unblock their account.