Blocking a user from your personal account→
You can block a user to deny them access to your activity and repositories, and to prevent them from sending you notifications.
Viewing users you've blocked from your personal account→
You can view a list of all users you've blocked from your personal account.
Unblocking a user from your personal account→
If you've mended fences with a GitHub user you've blocked, you can unblock their account.
Blocking a user from your organization→
Organization owners can block a user to remove the user's ability to collaborate in the organization's repositories.
Viewing users who are blocked from your organization→
You can view a list of all users whom you or other owners have blocked from your organization. If a user was blocked for a specific amount of time, you can see the amount of time they were blocked for.
Unblocking a user from your organization→
Organization owners can unblock a user who was previously blocked, restoring their access to the organization's repositories.
Reporting abuse or spam→
You can report behavior and content that violates community guidelines and terms.