After backlash from users, Twitter has hastily reversed a policy change on Thursday that could have allowed for harassment.

The social messaging site briefly modified its blocking policy to allow blocked accounts to operate under "shadow banning," where a blocked person could still view tweets, retweet and reply to a blocker. The catch is that the blocker wouldn't be able to see any of it.

Users quickly sounded off through the hashtag "#restoretheblock," Gawker reported via the AFP.

"We made #RestoreTheBlock happen," Katie Collins tweeted with the Twitter handle @GrlRedBalloon, thanking users of the service who "mobilized the troops," as quoted by the AFP.

#restoretheblock @Twitter, we don't feel safe here anymore. We'll leave. We'll do it. Watch us.

— Dr Tanta Tinycat (@drtantatinycat) December 13, 2013

Twitter, your dangerous users are YOUR problem. It's not MY JOB to fix them or do something about them. IT'S YOURS. #RestoreTheBlock — Wench (@kingdomofwench) December 13, 2013

I'm talking to you directly @twitter. I left FB for allowing my stalkers to find me. Don't make me feel unsafe on here too. #RESTORETHEBLOCK

— Suey Park (@suey_park) December 13, 2013

Now back under the normal blocking function, blocked accounts will have to log out or look through another account to view their blockers' tweets.

"Earlier today, we made a change to the way the 'block' function of Twitter works," Twitter's Michael Sippey said in a blog post late Thursday in California.

"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. Any blocks you had previously instituted are still in effect."

While in place, the change to how blocking works brought up concerns about harassment and other abuse.

Twitter officials briefly introduced the modified block to pacify anger from blocked accounts, based on the reasoning that the messaging service is essentially public anyway, according to the AFP.

"In reverting this change to the block function, users will once again be able to tell that they've been blocked," Sippey said.

"We believe this is not ideal, largely due to the retaliation against blocking users by blocked users (and sometimes their friends) that often occurs."

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