SAN FRANCISCO — Conservative Twitter users raged against the social media company, lobbing accusations of left-wing bias and censorship after thousands of followers were wiped out in an overnight bot purge.

The suspension of multiple accounts followed the indictment by special counsel Robert S. Mueller of Russian nationals for meddling in the U.S. election, including using fake accounts on Twitter to conduct “information warfare” against the United States. 

The hashtag #TwitterLockOut was trending in the U.S. on Wednesday morning as thousands of accounts, including those belonging to Michael Flynn Jr., son of former national security adviser Michael Flynn, and Infowars editor Paul Joseph Watson complained that hundreds, and in some cases thousands, of their followers had been shut down.

“The twitter purge is real,” Fox News commentator Dan Bongino wrote. “I woke up and saw I lost 100 or so followers,” columnist Adriana Cohen tweeted.

Twitter would not say how many accounts it purged.

“As part of our ongoing work in safety, we identify suspicious account behaviors that indicate automated activity or violations of our policies around having multiple accounts, or abuse,” the company said in a statement.

Twitter denied cracking down on conservative voices. “Twitter’s tools are apolitical, and we enforce our rules without political bias,” it said.

Social media services from Facebook to Google’s YouTube have been struggling to eradicate fake or abusive content without appearing to censor opinions. 

Bots — accounts powered by automated software, not people — have plagued Twitter for years. Researchers estimate as many as 15% of accounts on Twitter could be fake. Twitter says that number is lower.

Until scrutiny of bots intensified after the presidential election, Twitter had little incentive to remove fake accounts that pad its user and growth numbers, critics say. Last month, Twitter shut down more than 1 million fake accounts uncovered by a New York Times report.

According to Twitter’s rules, automated software is permitted to tweet but is banned from posting misleading or abusive content or spam. Twitter has begun rooting out and shutting down automated accounts linked to Russian disinformation campaigns.

Fake accounts on Twitter have been traced to a Kremlin-linked ”troll farm” accused of inflaming political divisions on hot-button national issues such as gun control after last week’s Florida school shooting. According to researchers at the University of Southern California, conservatives retweeted Russian trolls about 31 times more than liberals and produced 36 times more tweets. 

An organization that tracks Kremlin-backed Twitter accounts — the Alliance for Securing Democracy — says such influence operations have remained active since the election, serving to amplify disputes bubbling on the Web. On Wednesday, #twitterlockout and #twitterpurge were the top and trending hashtags used by the accounts linked to Russian influence operations tracked by the Alliance’s Hamilton 68 project.

In hearings last year, U.S. lawmakers criticized Twitter for not taking the Russian bot scourge seriously enough.

The overnight Twitter purge took some conservative users by surprise. A few complained they were temporarily locked out of their accounts because of “unusual activity” and “automated behavior” and had to share a phone number with Twitter to regain access.

Twitter said it asks account holders who may be in violation of its terms of service to provide a phone number “so we can confirm a human is behind it.”

“That’s why some people may be experiencing suspensions or locks,” the company said in a statement. “This is part of our ongoing, comprehensive efforts to make Twitter safer and healthier for everyone.”

Cutting off the fire hose of bot-generated content is a pressing issue for Twitter, which needs to grow its user base and attract more advertising. But conservative users and Trump supporters say Twitter deploys a double standard, unfairly singling out voices on the right.

White nationalist Jared Taylor sued Twitter on Tuesday for banning him from the service in December, claiming the company is discriminating against him for his political views. The suit filed in San Francisco Superior Court alleges Twitter violated a California law that protects free speech in public spaces. Taylor says Twitter cited its user agreement prohibiting accounts affiliated with groups that promote violence when it suspended his account. He denies that he or his group, New Century Foundation, promote violence or associate with groups that do.

In January, right-wing journalist-turned-entrepreneur Charles C. “Chuck” Johnson sued Twitter, alleging the company violated his right to free speech when it permanently suspended his account in 2015 after he asked for donations to “take out” civil rights activist DeRay Mckesson. Johnson said the tweet was not intended as a threat.

More: ‘Alt-right’ escalates war against Silicon Valley, pledges to expose bias against conservatives

More: Twitter accused of political bias in right-wing crackdown

More: Robert Mueller investigation: What is a Russian troll farm?

Last month, Project Veritas, a conservative advocacy organization that purports to expose media bias, released undercover videos of current and former Twitter employees condemning President Trump and discussing tactics the company uses to make it tougher to find the tweets of controversial users.

<!– –>