More brands are pulling away from Twitter advertising, including one of its biggest advertisers—Mondelēz—as the Elon Musk fallout continues.

Thursday turned into another dramatic day for Twitter’s embattled new owner, as more brands piled into the advertising exodus that started earlier this week. Meanwhile, new data shows a major slowdown in ad spend on the service, according to MikMak, an e-commerce service that has insights into performance on the platform. Advertisers told Ad Age that the risk and headache of Musk were not worth the hassle, as they prepared to spend money elsewhere.

These ad leaders, many of whom spoke on condition of anonymity, said that Musk decapitated the leadership at Twitter, losing people who marketers relied upon to trust the platform. This week, Sarah Personette, chief customer officer, and JP Maheu, VP of global client solutions, left the company. One marketing leader, at a major brand that paused spending on Twitter, said that the leadership strike was the last straw. “JP [Maheu] got walked out by security,” this marketing leader said. “Pretty much like a public hanging.”

“You’re getting rid of everyone who can calm the market and it’s not going well,” the exec said.

Related: Advertisers should pause Twitter ads, says Mediabrands

On Thursday, Mondelēz, a top 20 advertiser on Twitter at about $25 million in ad spend a year, paused ads globally on Twitter, according to people familiar with the move. Also, Pfizer and General Mills announced an ad freeze, according to The Wall Street Journal, which first reported on the latest brands to drop Twitter. On Tuesday, IPG’s Mediabrands told clients to pause advertising for at least a week, until Musk can deliver a plan around how it would keep Twitter safe from abuse. Last week, General Motors was the first major brand to announce it would pause spending on Twitter.

Twitter did not return a request for comment.

Musk has been a destabilizing force for Twitter since he started pursuing the company in April. Musk closed the $44 billion deal last week, and he has tried to assure advertisers that he would abide by certain standards of media quality that they have come to expect online. Advertisers feared Musk’s loose approach to moderation, in favor of unrestrained speech, would degrade the conversation on Twitter. Within days of taking over, there was evidence marketers were right to be afraid. There were reports of emboldened racist trolls using more slurs on Twitter. And Musk himself tweeted misinformation by sharing a false news story about the attack on Nancy Pelosi’s house.

On Thursday, Musk met with civil rights groups to try to smooth it all over, presenting his plan to form a council that would help moderate Twitter. Musk also made assurances about restoring access to moderation tools to more Twitter staff, according to Bloomberg News.

Advertisers were not just waiting for clear policies about moderation, but they also wanted an understanding of who would lead the advertising relationships, now that Personette and Maheu were gone. Robin Wheeler, a global client solutions leader at Twitter, has so far been filling the role left by Maheu, according to advertisers. Wheeler does not have the same level of support among brands, these advertisers said.

The uncertainty could hurt Twitter even more because brands are in the middle of planning their first quarter ad spend for next year, a period that includes Twitter’s biggest day of the year, the Super Bowl. “If I don’t know what’s going on by Thanksgiving, they lose everything for Q1,” said a marketing leader at a major brand, speaking on condition of anonymity.

There are clear signs that many brands have been pulling back on Twitter, according to Rachel Tipograph, the founder and CEO of MikMak, an e-commerce service that works with hundreds of major brands on digital ad campaigns, many on Twitter. “In the month of October, we’ve seen a 30% dip in Twitter, a dip in Twitter traffic,” Tipograph said on Thursday, “with so much of that dip occurring after the Elon Musk deal was announced.”

MikMak does not have a complete picture of every possible marketer on Twitter, but its ad service detects trends in referral traffic, which measures how many consumers a particular platform drives to a brand online. Referral traffic from Twitter had been growing all year, Tipograph said, although not nearly as much as, say, TikTok. In October, the Twitter referral traffic was down month over month, Tipograph said.

Not every agency has recommended to their advertisers to pull off Twitter, but the platform is particularly reliant on big brands. One ad insider told Ad Age that it seemed like many IPG clients heeded its advice to stop Twitter ads, but other major holding companies are taking a more measured approach. “We have had some clients asking how the [Twitter] sale might impact their Super Bowl plans,” another agency exec said, “but most seem to be taking a wait-and-see attitude, which is what we are advising right now. As always, we have multiple backup scenarios in place.”