Twitter accounts that offer to trade or sell child sexual abuse material under oblique terms and hashtags have remained active for months, despite CEO Elon Musk's promise to combat child exploitation on the platform.

“Priority #1,” Musk called it in a Nov. 20 tweet. He’s also criticized Twitter’s former leadership, claiming that they did little to address child sexual exploitation and that he intended to change things.

However, according to a single day's tweets, at least dozens of accounts have continued to post hundreds of tweets using terms, abbreviations, and hashtags indicating the sale of what Twitter calls child sexual exploitation material. Experts and law enforcement agencies working to combat the spread of such material are well aware of the signs and signals.

NBC News reviewed tweets that offered to sell or trade content commonly known as child pornography or child sexual abuse material. The tweets contain no Child sexual abuse material (CSAM), and NBC News did not view any CSAM while reporting this article.

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Some tweets and accounts date back months before Musk's takeover. They were still available on the platform as of Friday morning.

During Musk's tenure, many more tweets were published, which NBC News reviewed over a period of weeks. Some users who tweeted CSAM offers appeared to delete the tweets shortly after posting them, presumably to avoid detection, and then tweeted similar offers from the same accounts later.

“Twitter has zero tolerance towards any material that features or promotes child sexual exploitation, one of the most serious violations of the Twitter Rules. This may include media, text, illustrated or computer-generated images," according to Twitter’s rules published in October 2020. 

Twitter's vice president of product overseeing trust and safety, Ella Irwin, told NBC News in an email after this article was published, "We definitely know we still have work to do in the space, and certainly believe we have been improving rapidly and detecting far more than Twitter has detected in a long time, but we are deploying a number of things to continue to improve."

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Irwin asked that NBC News provide the findings of its investigation to the company so that it could "follow up and get the content down."

After Musk implemented several rounds of layoffs and issued an ultimatum that resulted in a wave of resignations, it's unknown how many people remain at Twitter to deal with CSAM. Musk has enlisted some outside assistance, and the company announced in December that the number of accounts suspended for child sexual exploitation had increased dramatically.

According to a representative for the National Center for Missing and Exploited Children, the number of reports of CSAM detected and flagged by the company has remained constant since Musk's takeover.