Darkweb fora dedicated to the illegal exchange of child sexual exploitation material (CSEM) continue to thrive. Profiling forum members based on their communication patterns will increase our insights in the dynamics of online CSEM and may aid law enforcement to identify those members who are most influential and pose the highest risk. The current study uses data from a large English language Darkweb CSEM forum that was active between 2010 and 2014, containing over 400,000 posts. Posts were time stamped, categorized based on subforum topic, and linked to individual forum members by nickname. Group-based trajectory modeling was subsequently applied to derive forum member profiles based on members’ posting history. Analyses show that over the course of the observation period, overall activity levels—in terms of total number of posting members and the average number of posts per month per member—fluctuate substantially and that multiple developmental pathways—in terms of monthly patterns in the frequency of posts by individual members—can be distinguished. Theoretical and practical ramifications of these findings are discussed.

致力于非法买卖儿童性剥削材料（CSEM）的Darkweb论坛继续蓬勃发展。根据论坛成员的交流方式进行分析，可以增加我们对在线CSEM动态的见解，并可以帮助执法人员确定最具影响力和风险最高的成员。当前的研究使用的是来自大型英语Darkweb CSEM论坛的数据，该论坛在2010年至2014年期间活跃，包含40万多个帖子。帖子带有时间戳，根据论坛主题进行分类，并通过昵称链接到各个论坛成员。随后将基于组的轨迹建模应用于基于成员的发布历史来导出论坛成员资料。分析表明，在观察期内，总体活动水平（根据发布成员的总数和每个成员每月平均发布的帖子数）波动很大，并且可以区分多种发展途径（就单个成员发布频率的月度模式而言）。讨论了这些发现的理论和实践意义。