Purpose This study aims to explore how the public perceives the effectiveness of surveillance technology, and how people’s views on privacy and their views on effectiveness are related. Likewise, it looks at the relation between perceptions of effectiveness and opinions on the acceptable cost of surveillance technology. Design/methodology/approach For this study, surveys of Dutch students and their parents were conducted over three consecutive years. Findings A key finding of this paper is that the public does not engage in a trade-off (...) neither with regard to privacy-effectiveness nor with effectiveness-cost, but rather expects all three elements to be achieved simultaneously. This paper also found that the correlation between perceived effectiveness and perceived privacy was stronger for parents than for students. Research limitations/implications Participants for this study were exclusively in The Netherlands. Survey questions on the effectiveness of surveillance technology focused on one type of technology, and on private mobile device use in two scenarios. Social implications The public’s perceptions of the effectiveness of surveillance technology potentially influence its acceptance of the technology, which, in turn, can affect the legitimacy and use of the technology. Originality/value Within the much-discussed privacy-security debate lies a less-heard debate – that of the effectiveness of the surveillance technology in question. The public is one actor in this debate. This study examines the public’s perceptions of this less-heard debate. (shrink)