This book argues that the rampant hate-filled attacks against women online are best understood as patterned resistance to women’s political voice and visibility. This abuse and harassment coalesces into an often-unrecognized form of gender inequality that constrains women’s use of digital public spaces, much as the pervasive threat of sexual intimidation and violence constrain women’s freedom and comfort in physical public spaces. What’s more, the abuse exacerbates inequality among women, those from racial, ethnic, religious, and/or other minority groups, are disproportionately targeted. Drawing on in-depth interviews with women who have been on the receiving end of digital hate, Credible Threat shows that the onslaught of epithets and stereotypes, rape threats, and unsolicited commentary about their physical appearance and sexual desirability come at great professional, personal, and psychological costs for the women targeted—and also with underexplored societal level costs that demand attention. When effective, identity-based attacks undermine women’s contributions to public discourse, create a climate of self-censorship, and at times, push women out of digital publics altogether. Given the uneven distribution of toxicity, those women whose voices are already most underrepresented (e.g., women in male-dominated fields, those from historically undervalued groups) are particularly at risk. In the end, identity-based attacks online erode civil liberties, diminish public discourse, limit the knowledge we have to inform policy and electoral decision making, and teach all women that activism and public service are unappealing, high-risk endeavors to be avoided.