Twitter has backtracked on a change it made to its "block" function after it faced a user revolt.
The short-lived change meant that blocked users could still view and interact with tweets from the person who blocked them and could no longer see that they had been blocked.
Twitter said this was designed to protect victims of harassment who feared that blocking a user would lead to retaliation.
But after a wave of online protest Twitter re-instated its previous policy, whereby blocked users are notified, and are prevented from following and interacting with their blocker.
Michael Sippey, vice president of product at Twitter, said: "We have decided to revert the change after receiving feedback from many users - we never want to introduce features at the cost of users feeling less safe."
Several online petitions had been launched and Twitter users rallied behind the hashtag #restoretheblock to complain about the change.
Dick Costolo, chief executive of Twitter, initially defended the change, explaining that it had been requested by victims of abuse.
He said on Twitter: "Now when you block a user, they cannot tell that you've blocked them. It was a longstanding request from users of block."
But Mr Costolo's comments did little to allay the mounting criticism of the change.
Suey Park said: "Dear @twitter, you protect abusers. You've let my stalkers invade my life and regain control. I will not back down."
Another Twitter user, Alaina Grey, added: "Don't make it easier for men to stalk our tweets and threaten us. We shouldn't have to be silent to feel safe."
Mr Sippey explained: "In reverting this change to the block function, users will once again be able to tell that they've been blocked."
He said that this "is not ideal" due to the retaliation against blocking users that can occur, adding: "Some users worry just as much about post-blocking retaliation as they do about pre-blocking abuse."
The social media site, which has more than 230 million monthly active users, was criticised earlier this year for not doing enough to curb online abuse against its users.
It came under pressure to tighten its regulations after bomb threat tweets were sent to three female journalists, and Labour MP Stella Creasy and campaigner Caroline Criado-Perez were targeted with rape threats.