Twitter’s head of trust and security says she’s resigned

() — Twitter’s head of trust and security, Ella Irwin, told Reuters on Thursday that she has resigned from the company.

In the role, Irwin oversaw content moderation as the company has faced criticism for lax protections against harmful posts since billionaire Elon Musk acquired it in October.

Irwin’s departure coincides with a time when the platform has struggled to keep advertisers, mainly because brands have been wary of appearing alongside inappropriate content.

Musk announced earlier this month that had hired Linda Yaccarinoformer head of advertising for NBCUniversal, as Twitter’s new CEP.

fortune reported previously reported that Irwin’s internal Slack account appeared to be disabled.