The growing popularity of social networking sites (SNS) and its increasing accessibility due to the advent of new technologies (such as smartphones and tablets, enabling users to be online more frequently) provide public health agencies with new opportunities for health pro-motion, prevention, disease control and research. However, the use of SNS by public health agencies raises ethical concerns. Mandeville et al. addressed a number of these concerns by means of an interesting case of contact tracing through Facebook around a patient with meningococcal septicaemia (Mandeville et al., 2013). Although the described situation is especially complicated due to the patient's incapability to provide informed consent, the unexpected interfer-ence of a proactive contact and the use of the patients' public Facebook 'wall', it clearly outlines the ethical issues surrounding the use of social media for contact tracing. Fortunately, most situations are less complex in daily practice of communicable disease control. SNS are here to stay. Although methods on how to use SNS most effectively in public health are understudied, evidence is growing that strategies including SNS can be more effective than traditional communication methods (Bennett and Glasgow, 2009; Gold et al., 2011; Bauermeister et al., 2012; Thackeray et al., 2012). In the area of communicable disease control, particularly for sexually transmitted infections, there are ample examples where SNS and Internet, in general, proved to be valuable tools for surveillance (Ginsberg et al., 2009; Signorini et al., 2011), reaching and involving target populations (Bull et al., 2004; Young, 2013; Young et al., 2013), or for learning more about (risk) perceptions and behaviors within these populations (Love et al., 2013). However, the use of SNS for contact tracing, a pri-mary means of control of infectious diseases with low prevalence, is relatively new. Since the effectiveness of contact tracing depends mainly on timeliness and com-pleteness of access to, and dissemination of, (correct) information in an individual's social network (Donnelly et al., 2003; Klinkenberg et al., 2006), applying SNS in this context also has promising prospects. During a