If someone has been harassing or spamming you on Twitter, blocking that person can be done in only a few seconds.
While blocking isn’t the last line of defense against these types of behaviors, it is one of the most effective.
Blocked users are not notified that they have been blocked, will not appear in your feed, and can be unblocked easily at a later time.
Blocking Someone on Twitter from Computer
To block someone from your home computer, log in to your Twitter account and head to the page of the person that you wish to block. This can also be done by navigating directly to the intended user’s Twitter URL.
Once on their page, select the Profile button that looks like a human silhouette to view a drop down menu. From this menu, select the “Block” option.
As mentioned, blocked users cannot add you to their lists, have replies mentioned in your feed, follow your account, or see your profile photos.
Unblocking Someone on Twitter from Computer
To unblock a user, start by visiting the page you have blocked. Because you won’t find any blocked user lists, searching for the user’s page through the Twitter search engine is the easiest way to find someone. Just enter their user name and select the correct name from the provided list.
Once you’re at the user’s Profile, click on the Profile icon and select “Unblock @UserName” from the drop down menu.
Blocking / Unblocking Someone on Twitter from iOS or Android Device
If you’re trying to block / unblock someone on your iPhone, iPad, or Android device, the process is nearly identical to desktop users.
Begin by finding the account you wish to unblock / block. Tap the user’s Profile button, and then tap “Block” or “Unblock” depending on your intent.
Keep in mind that if your account is public, a blocked user can still see your Tweets, and blocked users are also automatically unfollowed by default.