Washington, Jul 9 (AP) X CEO Linda Yaccarino said she's stepping down after two years running Elon Musk's social media platform.

Yaccarino posted a positive message Wednesday about her tenure at the company formerly known as Twitter and said “the best is yet to come as X enters a new chapter with” Musk's artificial intelligence company xAI, maker of the chatbot Grok.

Musk responded to Yaccarino's announcement with his own 5-word statement on X: “Thank you for your contributions.” Musk hired Yaccarino, a veteran ad executive, in May 2023 after buying Twitter for $44 billion in late 2022 and cutting most of its staff.

He said at the time that Yaccarino's role would be focused mainly on running the company's business operations, leaving him to focus on product design and new technology.

In accepting the job, Yaccarino was taking on the challenge of getting big brands back to advertising on the social media platform after months of upheaval following Musk's takeover.

A number of companies had pulled back on ad spending - the platform's chief source of revenue - over concerns that Musk's thinning of content restrictions was enabling hateful and toxic speech to flourish.

Two years later, those concerns have not subsided. A recent update to Grok led to a flood of antisemitic commentary from the chatbot this week that included praise of Adolf Hitler.

“We are aware of recent posts made by Grok and are actively working to remove the inappropriate posts,” the Grok account posted on X early Wednesday, without being more specific.

Some experts have tied Grok's behaviour to Musk's deliberate efforts to mold Grok as an alternative to chatbots he considers too “woke” such as OpenAI's ChatGPT and Google's Gemini. In late June, he invited X users to help train the chatbot on their commentary in a way that invited a flood of racist responses and conspiracy theories.

“Please reply to this post with divisive facts for @Grok training,” Musk said in the June 21 post. “By this I mean things that are politically incorrect, but nonetheless factually true.” A similar instruction was later baked into Grok's “prompts” that instruct it on how to respond, which told the chatbot to “not shy away from making claims which are politically incorrect, as long as they are well substantiated.” That part of the instructions was later deleted.

“To me, this has all the fingerprints of Elon's involvement,” said Talia Ringer, a professor of computer science at the University of Illinois Urbana-Champaign.

Yaccarino has not publicly commented on the latest hate speech controversy. She has, at times, ardently defended Musk's approach, including in a lawsuit against liberal advocacy group Media Matters for America over a report that claimed leading advertisers' posts on X were appearing alongside neo-Nazi and white nationalist content. The report led some advertisers to pause their activity on X.

A federal judge last year dismissed X's lawsuit against another nonprofit, the Centre for Countering Digital Hate, which has documented the increase in hate speech on the site since it was acquired by the Tesla owner.

X is also in an ongoing legal dispute with major advertisers - including CVS, Mars, Unilever, Lego, Nestle, Shell and Tyson Foods - over what it has alleged was a “massive advertiser boycott” that deprived the company of billions of dollars in revenue and violated antitrust laws. (AP) SCY SCY