We provide all Twitter users with the ability to block other users. Blocking prevents a user from following you, having their @replies to or mentions of your account show up in your Mentions tab, or from adding your account on any of their lists.
Blocked users can't:
Please note: If your Tweets are public (i.e., not protected), they will still be visible on your public profile page.
We do not send notification to a user when you block them, but because they will no longer be able to follow you, they may notice that they've been blocked.
If you change your mind, you can easily unblock a person by clicking Undo from the blocked user's profile page:
In addition to blocking users, you can also unfollow users or report accounts as spam. Please read those help pages for more information on unfollowing and reporting spam.
Our Troubleshooting articles for following issues have answers to common problems.