Academics do not typically expect their jobs to be dangerous, but they can be. As researchers seek to make their work accessible to broad audiences and leverage online platforms to share work widely, some find that visibility can expose them to harassment. This study examines the scope and nature of such harassment among educators across 12 social media platforms. We conducted exploratory semi-structured interviews with people who have encountered online harassment in their work and then used those findings to inform a large-scale survey of academics from universities in the United States to understand their experiences of harassment and of responding to harassment. Our findings identify contextual predictors and co-occurring attack types, offering recommendations for institutional strategies to better protect educators.