There is no single transparent global register of CMs. Much of the workforce remains hidden behind outsourcing chains and limited public reporting but it is a large and internationally dispersed workforce. There are around 15,000 people moderating Facebook and Instagram, with the overwhelming majority employed by third-party vendors, while about 10,000 were reviewing YouTube and other Google products.

This workforce operates across multiple regions, including the United States, the Philippines, India, Ireland, Portugal, Spain, Germany, Latvia, Kenya and elsewhere. It is multilingual and cross-cultural and moderators may be required to assess content across languages, dialects, cultural references and legal or policy frameworks that extend beyond their own immediate background, increasing the complexity and the burden of the role.

A substantial share of moderation work is carried out through outsourcing and vendor arrangements, often in countries where labour protections, visibility and access to support may be weaker although conditions vary across companies, contracts and local labour markets.  What remains consistent is that this large, globally dispersed workforce whose labour is essential to online safety but often under recognised and under supported.

CMs are also not a uniform workforce. They differ by age, gender, geography, language, employment status and life circumstances and these factors may shape how workers experience risk, support and safety in the role.

Types of decisions and materials

CMs do not only review obviously illegal material. Their work often spans several different categories of content and requires a mixture of policy knowledge, contextual judgement and rapid decision-making. In practice, this work often involves reviewing large volumes of content at speed, making repeated decisions under time pressure and moving quickly between very different kinds of material. Some cases are straightforward, but many are ambiguous, distressing or context dependent. Automated systems may filter content before it reaches a human reviewer, but human judgement remains necessary where content or context is complex.

Why public awareness is needed

1. Most parents, teachers and everyday users do not see the worst material online because someone else has already reviewed it and acted on it 
2. That hidden workforce includes moderators and Trust & Safety staff who identify and remove illegal or harmful content, including content linked to the sexual abuse and exploitation of children 
3. The role is not peripheral to online safety, it is part of the human infrastructure that helps protect children and prevents harmful, potentially traumatic material from reaching wider audiences 
4. Public discussion usually focuses on platforms, algorithms and regulation rather than on the people exposed to harmful or potentially traumatic material in order to make online spaces safer 

Evidence base

Key findings include: 

1. Peer-reviewed research shows that repeated exposure to extreme or distressing content is associated with trauma-relevant symptoms and secondary traumatic stress with higher exposure linked to higher psychological distress (Spence et al., 2023; Spence et al., 2024) 
2. A qualitative study with moderators exposed to child sexual abuse material identified intrusive imagery, triggering, avoidance, hypervigilance and negative cognitive and emotional effects consistent with repeated trauma exposure (Spence et al., 2023)
3. A cross-sectional survey of CMs from four lower and middle-income countries found high rates of PTSD symptoms, depression symptoms, somatic symptoms, and alcohol misuse (Gauthier et al., 2026).  
4. A comparison study found U.S. based CMs had higher PTSD and depression symptoms than colleagues who were not exposed to traumatic content (Gauthier et al., 2026). 
5. A replication and extension study found that problem-focused and approach-oriented coping strategies, including seeking support from similarly exposed colleagues, were associated with lower psychological distress and secondary trauma and with higher wellbeing while avoidant coping and confidentiality concerns were associated with poorer outcomes (Spence & DeMarco, 2025). 
6. A practitioner briefing highlighted the importance of peer support, supportive organisational policies, boundaries and recovery, while also underlining that wellbeing services are not a substitute for prevention-oriented controls on exposure and job demands (Spence, Martellozzo, & DeMarco, 2022; Spence & DeMarco, 2025). 

Why understanding matters? 

1. This role helps keep children safe and moderators are often among the first people to identify abusive or exploitative content and are part of the chain that enables removal, reporting and further action 
2. This role helps protect you from harmful, often traumatic material. The reason most users do not encounter the most disturbing content online is often because another human being has already had to see it 
3. The psychological cost is real and repeated exposure is associated with distress, posttraumatic stress, and other negative impacts. This should not be treated as an inevitable or invisible part of digital work 
4. Support alone is not enough and the evidence suggests that care matters but safer work design, reduced exposure, breaks, rotation and trusted support structures are also critical 
5. Responsibility should be shared. The burden should not rest solely on individual workers. Platforms, employers and policymakers all have a role in preventing avoidable harm. 

What better public understanding should lead to? 

Greater public awareness would mean recognizing that online safety depends not only on technology and regulation but also on human workers who are exposed to difficult and sometimes traumatic material.  It should also mean asking more informed questions about whether platforms and vendors are designing this work safely, including whether workers have realistic: expectations of the work prior to employment, workloads, exposure limits, breaks, peer support, confidential care and safe working conditions. Over time, more transparent public reporting on issues such as exposure, turnover, sickness absence, psychological incidents and support access could help show whether protections are improving in practice.