Apparently Twitter CEO Jack Dorsey is growing tired of insisting that Twitter's algorithm is purely "impartial" and doesn't discriminate against conservative voices.

As the controversy surrounding Twitter's blatant shadow-banning of conservative voices continues to rage, Dorsey admitted to lawmakers that his platform "unfairly" reduced the visibility of 600,000 accounts, including some members of Congress. But he refused to say whether a majority of them were Democrats or Republicans, only saying that the issues were remedied in late July.

Mr Dorsey told senators that the platform used "hundreds of signals" to decide "what to show, down-rank and filter." "We do not shadow-ban anyone based on political ideology," he said. "It was unfair," said Mr Dorsey. "We corrected it."

Dorsey told Senators that the platform used "hundreds of signals" to decide "what to show, down-rank and filter".

"Twitter does not use political ideology to make any decisions, whether related to ranking content on our service or how we enforce our rules," said Mr Dorsey.

Apparently, the market wasn't thrilled with his response as Twitter shares tanked, weighing on the Nasdaq for a second straight day on Thursday.

Meanwhile on Wednesday, the DOJ said it would investigate "growing concern that these companies may be hurting competition and intentionally stifling the free exchange of ideas on their platforms."

As the BBC points out, the allegations of censorship were fueled when Twitter added a "quality filter" to the platform and its search results. And then President Trump blew the issue wide open when he tweeted about it last month.

Twitter “SHADOW BANNING” prominent Republicans. Not good. We will look into this discriminatory and illegal practice at once! Many complaints. — Donald J. Trump (@realDonaldTrump) July 26, 2018

Here's a highlight of Dorsey's comments from the hearing (courtesy of the BBC):

Democrat Eliot Engel asked why Twitter did not require people to verify their identity when registering an account. Mr Dorsey said the platform had systems to detect bots and had prevented half a million fake accounts from even being used

Asked why Twitter relied on its users to report inappropriate content, Mr Dorsey said it was a "matter of scale" but that it responded quickly to reports based on their severity

Mr Pallone asked how many human moderators Twitter had in the US and how much they were paid. Mr Dorsey was unable to answer

Republican Fred Upton asked how Twitter determined whether somebody was trying to manipulate a conversation. Mr Dorsey said the platform was focused on "conversation health", with factors such as "shared attention" taken into account

Asked whether Twitter's rules were clear, Mr Dorsey said he accepted they were difficult to understand and needed to be "more approachable"

Republican Adam Kinzinger asked whether Twitter stored user data in Russia. Mr Dorsey replied that Twitter did not have servers in Russia

Republican Michael Doyle asked explicitly whether Twitter had taken action to censor conservatives. "No," replied Mr Dorsey

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Of course, in Dorsey's mind, these shadowbanning slip ups (and myriad other actions to repress conservative voices) don't mean twitter isn't "fair and balanced"...