Persons who engage in non-suicidal self-injury (NSSI), often conceal their practices which limits the examination and understanding of those who engage in NSSI. The goal of this research is to utilize public online social networks (namely, in LiveJournal, a major blogging network) to observe the NSSI population's communication in a naturally occurring setting. Specifically, LiveJournal users can publicly declare their interests. We collected the self-declared interests of 22,000 users who are members of or participate in 43 NSSI-related communities. We extracted a bimodal socio-semantic network of users and interests based on their similarity. The semantic subnetwork of interests contains NSSI terms (such as "self-injury" and "razors"), references to music performers (such as "Nine Inch Nails"), and general daily life and creativity related terms (such as "poetry" and "boys"). Assuming users are genuine in their declarations, the words reveal distinct patterns of interest and may signal keys to NSSI.