Others posted about violence. One member of the Facebook group wrote on Wednesday, “This is going to take more than talk to fix.” Underneath that post, another member responded with emojis of explosions.
On Thursday morning, the Stop the Steal Facebook group’s growth skyrocketed further, according to data from CrowdTangle, a Facebook-owned social media analytics tool.
That was when right-wing figures such as Jack Posobiec, a pro-Trump activist, and Amy Kremer, Ms. Kremer’s mother and a founder of a group called Women for Trump, began posting about the Facebook group on Twitter. Ali Alexander, a political operative who previously went by the name Ali Akbar, also tweeted dozens of times about the Stop the Steal movement to his 140,000 Twitter followers.
Their messages, which were shared thousands of times, were a rallying cry for people to join the Stop the Steal Facebook group and take action in local protests against voter fraud.
“In just it’s first couple hours, more than 100,000 people joined the Women for America First, Stop the Steal Facebook Group,” wrote Mr. Posobiec. In comments below his post, many people cheered the Facebook group’s popularity.
The tweets helped send more people to Stop the Steal. Interactions with the Facebook group soared to 36 posts a minute on Thursday morning, up from roughly one post a minute, according to CrowdTangle data.
Mr. Posobiec, Mr. Alexander and Amy Kremer did not immediately respond to requests for comment.
At Facebook, executives were notified of the group by Facebook moderators as they began flagging posts for potential calls for violence and protests to disrupt the vote. The company also received calls from journalists about the group and its explosive growth. By midmorning, executives were discussing whether they should remove Stop the Steal, said one employee involved in the discussions who was not authorized to speak publicly.