Many parents held up images of the children who died after falling prey to abusers on apps such as Instagram, TikTok and Snapchat

Mark Zuckerberg apologized to the parents of children who killed themselves after being subjected to online sexual exploitation during a US Senate hearing Wednesday. Evan Spiegel offered condolences to parents whose children obtained deadly illegal drugs via Snapchat. The words were too little, too late for their intended audience, though. The grieving guardians expressed only frustration with the social media CEOs’ responses to their plight and to questions from members of Congress.

“I’m not happy with the answers the CEOs are giving. They can’t give a straight answer. Not even ‘yes’ or ‘no,’” said Tammy Rodriguez, the mother of Selena Rodriguez, who was 11 when she died by suicide three years ago after being solicited for sexually exploitative content by strangers on Instagram and Snapchat.