CNN Business  — 

Twitter on Friday laid off thousands of employees in departments across the company, in a severe round of cost cutting that could potentially upend how one of the world’s most influential platforms operates one week after it was acquired by billionaire Elon Musk.

Numerous Twitter employees began posting on the platform Thursday night and Friday morning that they had already been locked out of their company email accounts ahead of the planned layoff notification. Some also shared blue hearts and salute emojis indicating they were out at the company.

By Friday morning, Twitter employees from departments including ethical AI, marketing and communication, search, public policy, wellness and other teams had tweeted about having been let go. Members of the curation team, which help elevate reliable information on the platform, including about elections, were also laid off, according to employee posts.

“Just got remotely logged out of my work laptop and removed from Slack,” one Twitter employee said on the platform. “So sad it had to end this way.”

Another employee said that she and other members of Twitter’s human rights team had been laid off. The employee added that she is proud of the team’s work “to protect those at-risk in global conflicts & crises including Ethiopia, Afghanistan, and Ukraine, and to defend the needs of those particularly at risk of human rights abuse by virtue of their social media presence, such as journalists & human rights defenders.”

Simon Balmain, a former Twitter senior community manager who was laid off Friday, said in an interview with CNN that he lost access to Slack, email and other internal systems around 8 hours before receiving an email Friday morning officially notifying him that he’d been fired. He added that the lay off email “still didn’t provide any details really” about why he’d been let go.

“The waves of annoyance and frustration and all that stuff are absolutely mitigated by the extreme solidarity we’ve seen from people that are in the company, people that are in the same position, people that left the company in years gone by,” Balmain said. “It’s like a giant support network, which has been absolutely amazing.”

One Twitter employee who was laid off told CNN Friday that some workers are relieved to have been let go. “For me, being safe would’ve been punishment,” the employee said.

While Twitter employees were posting about being laid off, Musk on Friday appeared for a friendly interview at an investor conference and spoke about making cheaper electric vehicles and his ambitions to go to Mars. During the interview, Musk said of Twitter, “I tried to get out of the deal,” but then added, “I think there is a tremendous amount of potential … and I think it could be one of the most valuable companies in the world.”

The interviewer said that Musk had laid off “half of Twitter” and Musk nodded, although he did not comment on the remark.

(In a series of tweets Friday evening, Yoel Roth, head of Twitter’s trust and safety team, confirmed overall headcount was cut by roughly 50%. The layoffs eliminated 15% of the company’s trust and safety team, leading to reductions in customer service but little change to content moderation, according to Roth. )

In his interview, Musk appeared to frame the sweeping layoffs as necessary for a company that, like other social media firms, was experiencing “revenue challenges” prior to his acquisition as advertisers rethink spending amid recession fears.

Musk also said “a number of major advertisers have stopped spending on Twitter” in the days since the acquisition was completed.

Elon Musk spoke at an investment conference Friday morning as employees at Twitter, which he now owns, were receiving notifications that they had been laid off from the company.

Twitter had about 7,500 workers prior to Musk’s takeover, meaning roughly 3,700 employees were laid off. The cuts come as Musk attempts to improve the company’s bottom line after taking out significant debt financing to fund his $44 billion acquisition.

The email sent Thursday evening notified employees that they would receive a notice by 12 p.m. ET Friday that informs them of their employment status.

“If your employment is not impacted, you will receive a notification via your Twitter email,” a copy of the email obtained by CNN said. “If your employment is impacted, you will receive a notification with next steps via your personal email.”

The email added that “to help ensure the safety” of employees and Twitter’s systems, the company’s offices “will be temporarily closed and all badge access will be suspended.”

The email concluded acknowledging that it will be “an incredibly challenging experience to go through” for the workforce.

Several Twitter employees on Thursday night filed a class action lawsuit alleging that Twitter is in violation of the federal and California Worker Adjustment and Retraining Notification Act (WARN Act) after laying off some employees already. The complaint was later amended to acknowledge that while several of the plaintiffs did ultimately receive sufficient notice of their termination under the WARN Act, Twitter still allegedly failed to give sufficient notice in the case of some employees.

The WARN Act requires that an employer with more than 100 employees must provide 60 days’ advanced written notice prior to a mass layoff “affecting 50 or more employees at a single site of employment.”

“Elon Musk, the richest man in the world, has made clear that he believes complying with federal labor laws is ‘trivial,’” Attorney Shannon Liss-Riordan, who filed the lawsuit, said in a statement to CNN. “We have filed this federal complaint to ensure that Twitter be held accountable to our laws and to prevent Twitter employees from unknowingly signing away their rights.”

WARN notices were filed by Twitter on Friday for nearly 1,000 impacted employees at the company’s various California offices.

Separately, other labor lawyers told CNN Friday they had begun receiving inquiries from Twitter employees questioning whether their terminations may have been unlawfully discriminatory or retaliatory.

“Former Twitter employees have reached out to us regarding their layoffs and their circumstances, and so we’re looking at all the issues — beyond appropriate notice — and to make sure the employee wasn’t laid off due to their membership in a protected category,” said Chauniqua Young, a partner at the law firm Outten & Golden.

Beyond the potential for lawsuits arising from the layoffs, other legal experts say Musk’s handling of the cuts may well create further problems for him down the road — whether in terms of attracting future talent or by keeping remaining workers satisfied.

“Once you treat people like this, they remember that,” said Terri Gerstein, a fellow at Harvard Law School’s Labor and Worklife Program and Economic Policy Institute. “Of the people remaining, it is a certainty that none of them feel secure in their job, and I would be shocked if the remaining people were not updating their resumes right now or talking with each other about starting a union.”

Musk started his tenure at Twitter by firing CEO Parag Agrawal and two other executives, according to two people familiar with the decision.

And in less than a week since Musk acquired the company, its C-suite appears to have almost entirely cleared out, through a mix of firings and resignations. Musk has also dissolved Twitter’s former board of directors.

Many staffers on Friday summed up their feelings with a hashtag, #LoveWhereYouWorked, a past-tense play on one previously often used by Twitter employees.

- Brian Fung and Shawn Nottingham contributed to this report