The tipping point for Haugen came in the spring of 2021, after her team was dispersed to other initiatives across the company. She resigned and later leaked thousands of internal documents to The Wall Street Journal. The Journal's reporting on the materials revealed Facebook's awareness of some of the detrimental effects that activity on its platforms, which include Instagram and WhatsApp, appeared to be having on users—from Instagram's impact on the mental health of teenage girls to how Facebook was being used to spread hate and incite violence against vulnerable populations.