Donald Trump is allowed back on his longtime social media app of choice: Twitter. While many under new owner Elon Musk to lift its ban on the former president, other folks aren’t happy. Civil rights groups like the NAACP, the Anti-Defamation League, and Color of Change have criticized Musk’s decision to reinstate Trump, arguing that the , and that Musk has been erratic and unclear in his decision-making process. Further fanning the flames is the fact that Twitter has also of several controversial and far-right public figures, and . Inevitably, the series of decisions demonstrates the singular power that Musk, the world’s richest man, has over the major social media platform he now owns.

Musk announced the Trump decision in a tweet on Saturday evening, reversing Twitter’s permanent ban on the former president after his supporters stormed the capitol on January 6, 2021. The decision comes just days after Trump announced his candidacy for president in the 2024 election.

Musk’s decision to bring back Trump followed a poll he had posted Friday on Twitter saying, “Reinstate former President Trump” that let users vote “Yes” or “No.” At the time Musk announced his decision, around 52 percent of over 15 million respondents on his poll voted in favor of bringing Trump back and 48 percent voted against. Trump’s account became active soon after Musk’s announcement, and his tweets became visible again. So far, though, Trump seems to have snubbed his old platform of choice. As of Monday afternoon, he had not posted any new tweets since his account was reinstated and has recently said that he has “no intention” of returning to the platform. Regardless of whether Trump starts tweeting again, Musk’s decision is as polarizing as Trump himself.

Adding to the concern, Twitter has reinstated the accounts of other public figures who were suspended after posting controversial speech on Twitter, such as who previously tweeted he would go “defcon 3” on Jewish people; Canadian psychologist , who was ; , who tweeted that women who are sexually assaulted bear some responsibility; and Rep. Marjorie Taylor Greene (R-GA), who was suspended for .

This isn’t surprising considering that Musk bought Twitter with the intention of letting people say whatever they want on the platform, as long as it isn’t illegal. Musk, however, has deviated from his “free speech absolutist” ideology in upholding Twitter’s ban on right-wing extremist influencer Alex Jones, who promoted a conspiracy theory that the Sandy Hook school shooting, which left 20 children dead, was a staged event. Musk “no mercy for anyone who would use the deaths of children for gain, politics or fame.”

The fact that Musk is selectively enforcing rules around acceptable speech on Twitter at his own discretion has prompted criticism. Musk has long signaled that he was in favor of bringing Trump back to Twitter, but he also said he’d wait on reinstating any banned accounts until with “widely divergent views” to advise. Now, Musk has gone ahead and made his decision about Trump seemingly based on his own decision and his impromptu Twitter poll. That has angered civil rights groups leaders, who criticized Musk’s poll as being ad hoc and unrepresentative of the US population. Anti-Defamation League CEO Jonathan Greenblatt tweeted that Musk is “not remotely serious about safeguarding the platform from hate, harassment and misinformation,” to which Musk replied, “Hey stop defaming me!”

Some argue that Musk’s decision to reinstate Trump could be inconsequential if the former president doesn’t start tweeting again.

Trump has previously said that he would not return to Twitter if given the chance because he’d rather stay on Truth Social, the social media app he founded in February. Speaking at the Republican Jewish Coalition’s annual leadership meeting on Saturday just before his Twitter account was reinstated, and that his own social media app, Truth Social, had better engagement than Twitter and is doing “phenomenally well.” But there’s reason to be skeptical of that. Trump has tens of millions more followers on Twitter: 88 million at his peak on Twitter versus less than 4 million on Truth Social in September. Twitter may also offer a better ability to reach not just his fans but his haters, too.

“He can be the fox in the henhouse again, so to speak” Katie Harbath, a social media policy consultant and former Facebook public policy employee, told Recode. “Twitter is the place you want to be to needle the folks that are unsupportive.”

Musk’s decision could also make it easier for other major social media platforms like Facebook to reinstate Trump. Meta, Facebook’s parent company, had said that it would reconsider whether Trump posed an , and has previously sought advice from its independent oversight board on the matter.

In the months after Trump was banned from Twitter, there was a precipitous drop in the amount that people talked about him across major social media platforms. If Trump were to return to Twitter, we could see an increase in the volume of conversations about the former president.

Update, November 21, 4:21 pm ET: This story, originally published on November 19, has been updated to include reactions to the reinstatement of Trump’s Twitter account and other notable account reinstatements.