Senate to Subpoena Twitter CEO Over Blocking of Disputed Biden Articles

GOP lawmakers are singling out Twitter because it prevented users from posting links to the articles, which the Post said were based on email exchanges with Hunter Biden, the Democratic candidate’s son, provided by allies of President Trump. Those people in turn said they received them from a computer-repair person who found them on a laptop, according to the Post.

The Wall Street Journal hasn’t independently verified the Post articles.

“This is election interference, and we are 19 days out from an election,” Sen. Ted Cruz (R., Texas), a committee member who discussed the subpoena with Senate Judiciary Committee Chairman Lindsey Graham (R., S.C.), told reporters. “Never before have we seen active censorship of a major press publication with serious allegations of corruption of one of the two candidates for president.”

A Twitter spokesperson declined to comment on lawmakers’ subpoena threat.

Thursday evening Twitter’s legal and policy chief, Vijaya Gadde, said the company would change how it enforces certain content rules, citing “significant feedback” on how it handled recent articles from the New York Post.

“We will no longer remove hacked content unless it is directly shared by hackers or those acting in concert with them,” she wrote, saying that Twitter instead would seek to put such material in context. “We believe that labeling Tweets and empowering people to assess content for themselves better serves the public interest.”

Twitter and Facebook Inc. separately took steps to limit the distribution of the Post articles published Wednesday on their platforms.

While Facebook didn’t prevent users from sharing the articles, it flagged the content for its third-party fact-checkers to review, a step that reduces the likelihood they will appear in users’ news feeds.

Twitter blocked users from posting links to the Post articles, initially citing a potential violation of its rules regarding hacked materials. The company later said the content also violated its policies on displaying private information like email addresses and phone numbers without a person’s permission. Mr. Dorsey tweeted late Wednesday that the company’s communications about its actions weren’t ideal and that blocking sharing links without context was unacceptable.

The Post articles, published Wednesday morning, cited emails it said were written and received by Hunter Biden. One article included a copy of an email said to have been sent to Hunter Biden apparently describing a meeting between his father and an executive at the Ukrainian energy firm Burisma Holdings, on whose board Hunter Biden served.

The Biden campaign challenged the Post’s reporting.

“The New York Post never asked the Biden campaign about the critical elements of this story,” spokesman Andrew Bates said in a statement. “They certainly never raised that Rudy Giuliani—whose discredited conspiracy theories and alliance with figures connected to Russian intelligence have been widely reported—claimed to have such materials,” he said, referring to the president’s personal lawyer whom the Post said acquired the emails.

“Moreover, we have reviewed Joe Biden’s official schedules from the time and no meeting, as alleged by the New York Post, ever took place,” Mr. Bates said.

The Post published a new article Thursday about Hunter Biden from what it said was the trove of emails it obtained. News Corp, the corporate parent of Journal publisher Dow Jones & Co., also owns the New York Post.

The Senate’s subpoena of Mr. Dorsey escalates a long-running battle between Republicans and social-media companies, which conservatives see as biased in favor of liberal viewpoints.

It also revives a line of attack that Mr. Trump used during impeachment proceedings against him, which focused in part on his withholding of aid to Ukraine and his repeatedly pressing the country to announce investigations into the Bidens that could benefit him politically. At the time, the president and his allies had attempted to put the spotlight on Hunter Biden’s service on Burisma’s board while Joe Biden was working as vice president on issues related to Ukraine. Mr. Trump was acquitted of both articles of impeachment in February.

Hunter Biden has denied wrongdoing and said it showed poor judgment to serve on the company’s board. During his time as vice president, Mr. Biden sought the removal of a Ukrainian prosecutor involved in investigating the company as part of a broad international effort to combat corruption in Ukraine.

Sen. Josh Hawley of Missouri, another Republican member of the Judiciary Committee, said he wanted Facebook to testify as well. Facebook had also limited distribution of the Post’s articles on its platform, saying it was awaiting guidance from its third-party fact-checking partners—independent organizations that routinely review the accuracy of viral content.

Thomas Rid, a professor of strategic studies at Johns Hopkins University who studies cybersecurity and election interference, earlier told the Journal that social-media companies are “doing the right thing by being cautious here.”

Mr. Rid said there have been instances of last-minute email dumps as part of disinformation campaigns ahead of elections. While the source of the emails in question could be legitimate, he said, the timing and lack of independently verifiable information raises a number of red flags.

—Sarah E. Needleman, Jeff Horwitz and Robert McMillan contributed to this article.

Write to Siobhan Hughes at [email protected]