Camera traps are widely used in conservation research and practice. They can capture images of people (‘human bycatch’), but little is known about how often this happens, or the implications for human rights, wellbeing, or conservation. We surveyed authors of published ecology and conservation studies that used camera traps. Over 90 percent of respondents reported that their projects had captured images of people, in most cases unintentionally. Despite this, images of people were widely used to inform conservation practice, demonstrating that camera traps are a key tool in emerging regimes of conservation surveillance. Human behaviour caught on camera included illegal activities and acts of protest. Some respondents reported positive conservation impacts of human bycatch, for example in law enforcement. However, others reported negative social impacts, such as infringing privacy and creating fear. We argue that these findings reveal a breach of commitment to do no harm and could undermine conservation success if they exacerbate conflict. Over 75 percent of respondents reported objections to or direct interference with camera traps, confirming opposition to their deployment. Many respondents recognise and take steps to mitigate these issues, but they are rarely discussed in the literature. Policy guidelines are needed to ensure the use of camera traps is ethically appropriate