The US Securities and Exchange Commission (SEC) charged boxing legend Floyd Mayweather and music producer DJ Khaled with illegally promoting investments in initial cryptocurrency coin offerings (ICOs).

CCN reports that the two celebrities “had been among the most prolific ICO promoters, pumping crypto tokens on social media while sometimes failing to disclose that the posts — which in several cases promoted illegal securities offerings — were paid-for advertisements.”

According to the SEC, cryptocurrency coins sold in ICOs may be considered securities and are subject to federal securities laws. Mayweather failed to disclose that he received $300,000 from three separate ICO issuers, including $100,000 from Centra Tech. Meanwhile, Khaled failed to disclose a payment of $50,000 from the same company.

Both Khaled and Mayweather agreed to pay disgorgement, penalties, and interest to the SEC, though neither celebrity admitted or denied the findings. The two also agreed not to promote any securities, including digital ones, for two and three years, according to the SEC.

Khaled and Mayweather promoted Centra’s ICO on their social media accounts, in which Khaled called it a “game changer,” while Mayweather encouraged his followers to take part in the ICOs, he too has partaken in.

“You can call me Floyd Crypto Mayweather from now on,” he tweeted.

The SEC made clear that ICOs can be fraudulent, while it also encourages potential investors to be cautious of those ICOs that are endorsed by celebrities. “With no disclosure about the payments, Mayweather and Khaled’s ICO promotions may have appeared to be unbiased, rather than paid endorsements,” said SEC Enforcement Division co-director Stephanie Avakian.

“Social media influencers are often paid promoters, not investment professionals, and the securities they’re touting, regardless of whether they are issued using traditional certificates or on the blockchain, could be frauds,” said Steven Peikin, another SEC enforcement division co-director.