The blocking feature will be removed for users of X, formerly Twitter, Elon Musk has announced, claiming the feature "makes no sense".
The X boss said users will still be able to block people from directly messaging them, however.
But many people on social media said it will make it hard for people to remove abusive posts from their timeline.
It is the latest in a series of changes Mr Musk has made since taking over the site in a $44bn deal last year.
Currently, when users "block" an account, it stops that account's posts from appearing in the blocker's timeline, and vice versa.
An account that is blocked can no longer send messages to the blocker, nor can it view their posts.
Former Twitter founder, Jack Dorsey, seemed to agree with Mr Musk's decision, posting: "100%. Mute only".
But there are concerns that muting an account would not be sufficient protection from cases of harassment, abuse or stalking.
The mute function currently only stops notifications about an account's posts. An account that is muted can still view the muter's posts and reply to them.
Removing a blocking feature could also potentially violate the terms and conditions of stores like Apple's App Store and Google Play.
Both stores have conditions stating that social media apps should allow users facilities to filter harassment or bullying.
It could mean X is no longer downloadable from those stores.