One of the biggest challenges facing the tobacco control community today is how to address the high rates of smoking by groups experiencing social and/or economic disadvantage. For example, half of all smokers in Australia are the most socio-economically disadvantaged members of society 1. This pattern is evident in most high-income countries where smoking rates are high among people with a mental illness or drug addiction, who are unemployed or homeless and who are in the lowest socio-economic groups 2. These social groups have been exposed to the same levels and types of tobacco control measures as the rest of the population yet, unlike the rest of the population, cessation rates are low and smoking remains widespread. It is increasingly acknowledged that different treatment approaches may be required, including tobacco harm reduction 3. Hall et al., in this issue of the Journal, present arguments to show that banning electronic (e-) cigarettes is likely to increase inequity and challenge ethical principles 4. They argue that e-cigarettes could be an effective tobacco harm reduction strategy and they present two alternative pathways for the retailing of e-cigarettes—‘levelling up’ to allow e-cigarettes to be sold like tobacco cigarettes or ‘levelling down’ to impose the same restrictions on tobacco cigarettes as apply to e-cigarettes 4. Research on e-cigarettes is in its infancy and, as with most tobacco research, has been focused on the general population. Given that many smokers are from disadvantaged groups, it is important to consider whether e-cigarettes have a differential impact on smokers from these groups 2. However, only limited data are available. A large-scale study in the United States found that smokers with mental illness were more likely to try e-cigarettes, be current users and be interested in future use than those without a mental illness 5. Using e-cigarettes to ‘try to quit smoking’ or ‘as a safer alternative to tobacco cigarettes’ were two of the three most common reasons for using them, with ‘just because’ reported as the most common reason. This mirrors our unpublished data with 369 socio-economically disadvantaged smokers from Australian community welfare services, which show high awareness and use of e-cigarettes and the perception that they are safe. The results suggest that people who are disadvantaged or with a mental illness are more open to the idea of using e-cigarettes, whether it is as a quitting aid, for harm reduction or ‘just because’. With limited evidence, and no government and tobacco control sanctioned awareness campaigns for e-cigarettes, the question arises—from where are people getting information about the safety and efficacy of e-cigarettes? One explanation is manufacturers marketing e-cigarettes as a treatment for mental health conditions 5. No doubt the tobacco control community need to ‘catch up’ in handling electronic cigarette public education, particularly among more vulnerable groups that are currently being targeted by manufacturers. Similar targeting is occurring among prisoners in the United States 6. There are only two small trials of e-cigarettes for smoking cessation or reduction with disadvantaged smokers. A pilot study of 14 smokers with schizophrenia who were not interested in quitting showed that e-cigarette use reduced tobacco cigarette consumption significantly over a 12-month period with no negative effects 7. A secondary analysis of the smoking outcomes data of a randomized trial of e-cigarettes compared with nicotine patches and placebo with a subsample of 86 participants with mental illness found no significant differences between groups in cessation rates, but higher reduction of cigarettes smoked and greater acceptability and treatment compliance in the group receiving the e-cigarettes 8. Treatment compliance and retention is an important issue generally in tobacco dependence treatment with reports of nicotine replacement therapy (NRT) compliance often low, particularly among socio-economically disadvantaged groups. If e-cigarettes are a more acceptable form of nicotine substitution for smokers in disadvantaged groups, they may result in higher cessation and reduction outcomes among groups notoriously difficult to change 9. Applying the ‘levelling down’ approach outlined by Hall et al. may introduce the public health benefits of e-cigarettes to groups of smokers who are only exposed to the extreme forms of tobacco-related harms. The Hall et al. paper raises important policy and ethical issues about the availability of e-cigarettes. The idea of tobacco harm reduction is central, and no one could benefit more from tobacco harm reduction than socio-economic groups who experience tobacco-related harm at disproportionately high rates. Further debate and research on e-cigarettes must be conducted through an equity lens to ensure that those at highest risk of harm are most likely to gain benefits. None. B.B. is supported by a National Health and Medical Research Council (NHMRC) Career Development Fellowship and a University of Newcastle, Faculty of Health and Medicine, Gladys M. Brawn Career Development Award.