Online social network members provide more varied and impartial support within a reduced-risk environment; however, not all online observers react favorably when viewing a support-seeking message. Grounded in the attribution-emotion-action model, this study examines how responsibility for stigma, coping effort, and message visibility influence observers’ emotions and verbal person-centered responses when viewing a support-seeking message on Facebook. Results from an experiment ( N = 798) indicated observers’ feelings of sympathy mediate the association between responsibility for stigma and verbal person-centered responses, but only when coping effort is high. Analyses also revealed effects related to message visibility, such that observers reported higher levels of sympathy when a seeker indicated lower responsibility for stigma and higher effort in a private message, which then elicited higher verbal person-centered responses. Results have implications for the attribution-emotion-action model and communication theory of visibility and offer practical insights for people seeking support for stigmatized health conditions.