Expressions of discomfort or concern with interventions by radical social science movements, such as Critical Management Studies (CMS) or Science and Technology Studies (STS) in public controversies have rested heavily on two concerns: fi rst, that radical social science is not useful to institutions like business and, second, that, in order to make themselves useful such interventions must compromise the radicalism of the social science program. A third concern has been that intervention is not the job of the social scientist. Recently, my and others' interpretations of my own intervention in law in one case have become something of an object lesson in the perils and pitfalls posed by legal interventions by STS scholars. This paper presents a more optimistic interpretation of my intervention experiences in fi ngerprint cases based on a broader array of experience than that single case. I suggest, fi rst, that we may need to think more carefully about how to measure the utility of critical social science interventions. Second, I suggest that there may be cases in which building alliances with mainstream scientifi c institutions may not necessarily constitute a failure of radicalism. I conclude by suggesting that the evaluation of expert knowledge is the job of STS, if it 'means business'.