Twitter has hit back against accusations of shadow banning prominent Republicans on Wednesday, with founder and CEO Jack Dorsey insisting that the company does not engage in the practice. He did, however, concede in a tweet that his company needed to do more to build public trust.

“A short thread addressing some issues folks are encountering as a result of our conversational health work, specifically the perception of ‘shadow banning’ based on content or ideology,” he said, while quoting a prior lengthy explanation from Twitter product lead, Kayvon Beykpour.

“It suffices to say we have a lot more work to do to earn people’s trust on how we work,” Dorsey added.

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A short thread addressing some issues folks are encountering as a result of our conversational health work, specifically the perception of “shadowbanning” based on content or ideology. It suffices to say we have a lot more work to do to earn people’s trust on how we work. https://t.co/MN97l7w7RF

— jack (@jack) July 25, 2018

Shadow banning is defined as the act of blocking a user or their content from an online community such as Twitter so that it won’t be readily apparent to the user that they’ve been banned.

Dorsey’s statement on the matter was prompted by a Vice News article published Wednesday, which found that a number of prominent Republicans were not autofilling in the social media platform’s search bar. The issue did not affect any Democrats, Vice found.

In Beykpour’s thread, which you can read here, he said the reason some prominent conservative’s names didn’t autofill was not nefarious relating to their political affiliation but rather was based on “behavioral signals” used to downgrade accounts that were not “healthy” to the public discourse.

“In May, we started using behavioral signals and machine learning to reduce people’s ability to detract from healthy public conversation on Twitter. This approach looks at account behavior and interactions with other accounts that violate our rules,” he explained. “Some accounts weren’t being auto-suggested even when people were searching for their specific name. Our usage of the behavior signals within search was causing this to happen & making search results seem inaccurate. We’re making a change today that will improve this.”

Though allegations of shadow banning on Twitter have long percolated in conservative media, most members of Twitter’s media blue check community have laughed it off.

“Must admit that when some [Republican] sources have complained about this to me I mocked them to their face as conspiracy theorists,” said Axios’ Jonathan Swan. He said the Vice report had caused him to rethink the issue.

Reps to Twitter did not immediately respond to The Wrap’s request for any additional comment.