For whatever reason you don't want to read notices of someone, you can block other users. They are then forcedly unsubscribed from your account and can not resubscribe to you. Further they can no longer send you @-replies.
You find the block button in their profile and in your subscribers/subscriptions lists.
- Personal timeline should hide or delete already-existing posts by blocked user
- issue 2096
- Advanced Blocking: avoid @-replies to blocked users & blocked users when logged in
- issue 2384
- Group timeline view should hide notices by profiles blocked by the current user
- issue 2735