An Investigation of the Portrayal of Social Media Challenges on YouTube and Twitter. - Amro Khasawneh; Kapil Chalil Madathil; Heidi Zinzow; Pamela J. Wisniewski; Amal Ponathil; Hunter Rogers; Sruthy Agnisarman; Rebecca Roth; Meera Narasimhan (ACM Trans. Soc. Comput., 2021)