The logo for Twitter is seen on the floor of the New York Stock Exchange on Feb. 8, 2018. (Richard Drew/Associated Press)

The social-media service Twitter is believed to have suspended thousands of accounts for being automated bots or for other policy violations, drawing outcry from fringe conservative media figures who lost followers in the move.

Many of these figures, such as pro-Trump host Bill Mitchell and white nationalist Richard Spencer, took to the service to complain about losing a small portion of their followers in the move. Other conservative accounts were suspended pending verification that they are run by people.

Twitter did not confirm the number of accounts that it suspended but released a statement saying that it was continuing to identify “suspicious account behaviors” that represented automated activity or other violations of its terms of service.

The company said that its work to remove malicious and fake accounts from its service included asking users to confirm a phone number so they can “confirm a human is behind it.”

“That’s why some people may be experiencing suspensions or locks,” the company said in a statement from spokeswoman Emily Horne. “Note that when an account is locked and being challenged to provide a phone number, it is removed from follower counts until it provides a phone number. This is part of our ongoing, comprehensive efforts to make Twitter safer and healthier for everyone.”

The move comes as Twitter is under increased scrutiny nationally for its role, however unintentional, in becoming a platform for false, misleading and hateful information in the run-up to the 2016 election and afterward, along with other leading social-media and technology companies such as Google and Facebook. Special counsel Robert S. Mueller III, who is investigating Russian interference in the 2016 election, listed the company in a recent court complaint as one of the main targets of a sophisticated and illegal propaganda operation run by a Kremlin-linked troll farm in St. Petersburg.

In response to the criticism, Twitter has taken some steps to improve its service, weeding out more than 50,000 accounts that it identified as being linked to Russia and its operatives, and notifying nearly 700,000 users who interacted with these accounts.

It has also sought to tamp down some forms of abusive or hate speech on the service. In November, it removed its blue check marks — which it gives out to verify users’ identities — from many far-right and white nationalist and supremacist accounts, including Spencer’s.

These moves have drawn criticism from far-right and pro-Trump figures — many of whom have followed President Trump’s cues to use the service to spread false information — that the technology company is politically biased against them.

But there are many signs that the service is still being used maliciously to amplify partisan themes and spread misinformation with the help of bots.

Automated Twitter accounts are believed to have helped popularize the hashtag #releasethememo to drum up support for the release of a memo that House Intelligence Committee Chairman Devin Nunes (R-Calif.) compiled to discredit the Russia investigation.

After the Parkland school shooting last week, networks of accounts suspected of having links to Russia switched from tweeting about Mueller’s investigation to amplifying hashtags about the gun-control debate.

On Tuesday, the most popular hashtags pushed by these networks were #twitterlockout and #twitterpurge, according to the Alliance for Securing Democracy, which tracks such networks.

Some mocked the conservative complaints on Tuesday as being relatively trivial.

Spencer, who has called for an “ethnic cleansing” of the United States that he claims would be peaceful, complained of losing about 1 percent — fewer than 1,000 — of his 80,000 Twitter followers.

Other users complained of having to reauthenticate their accounts with their phone numbers.

Mike Cernovich, a pro-Trump media figure with a history of spreading conspiracy theories, wrote in a text message that “Trump people and conservatives generally feel there are social media double standards, and this confirms it for them.”

Cernovich is suing the long-form platform Medium after its recent barring of him and others with histories of spreading false or misleading information.

Craig Timberg contributed to this report.

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