President Donald Trump signed an executive order on Thursday that served as a warning to Twitter and Facebook not to mess with his accounts, or accounts run by fellow conservatives, just as the 2020 election kicks into high gear.

The move drew a rebuke from Interactive Advertising Bureau CEO Randall Rothenberg. In a statement, he described it as a threat to both consumers and the overall ad industry. Trump's order also highlighted the diverging strategies Facebook and Twitter are taking as social media referees in this high-stakes political environment. 

The executive order takes aim at Section 230 of the Communications Decency Act, which grants immunity to internet platforms, freeing them from responsibility over the content published on their sites. "Large social media platforms, such as Twitter and Facebook, as the functional equivalent of a traditional public forum, should not infringe on protected speech," the executive order states. 

The president’s move comes just two days after Twitter placed a “get the facts” label on two of Trump’s tweets which suggested mail-in ballots could be suspect to voter fraud. It was the first time the social media company had placed such a label on Trump's tweets. Trump described Twitter’s decision as similar to “political activism.”

“The choices Twitter makes when it chooses to suppress, edit, blacklist, shadowban are editorial decisions pure and simple,” Trump said during the signing on Thursday. “In those moments Twitter ceases to be a neutral public platform and it becomes an editor with a viewpoint.”

“I think we can say that about others, also — whether you are looking at Google, whether you are looking at Facebook and perhaps others,” he added.

Trump's view is shared by some conservative lawmakers who claim platforms lose immunity when they act as publishers by moderating and editorializing on their sites. But many legal experts and regulators do not support that interpretation, leaving Trump’s executive order constitutionally questionable.  

Rothenberg took the latter view. “The president’s draft executive order is the gravest assault on the right to free speech since the Nixon administration and an attempt to turn the open and advertising-supported internet into a political arm of the U.S. government,” he stated. “It’s a familiar tactic of juntas in places like Pakistan and Argentina, and will not gain traction in the United States, because it clearly oversteps the bounds of executive authority, attempts to subvert more than 200 years of first amendment law, won’t stand in court and won’t gain congressional approval.”

Facebook and Twitter have charted separate courses when it comes to political activity. For instance, last year, Twitter decided to ban political campaign ads, while Facebook said it would continue to allow them. That was after Democratic candidates for president pressured both companies over not fact-checking ads. On Thursday, in an interview with Fox News, Zuckerberg reiterated the position he has said many times: “I just believe strongly that Facebook shouldn’t be the arbiter of truth of everything that people say online,” he said. Still, he was critical of Trump's position against section 230, and said repealing it would only increase the need for internet companies to police speech on their services.

Twitter CEO Jack Dorsey took what appeared to be a more defiant stance, defending his company's actions that prompted the executive order. “There is someone ultimately accountable for our actions as a company, and that’s me. Please leave our employees out of this,” Dorsey tweeted. “We’ll continue to point out incorrect or disputed information about elections globally. And we will admit to and own any mistakes we make.” 

Trump is a powerful force in social media even without the presidency. His frequent Twitter usage, where he has 80.4 million followers, helped propel him to the White House, and his campaign is a prolific Facebook advertiser. In the past 90 days alone, the Trump campaign and his committee have spent a combined $7.8 million on Facebook ads, according to Facebook’s public ads records.