As we have seen in the introductory chapters to this book, illicit antiquities are often inserted into legitimate supply chains. The question arises, how much do these ‘legitimate’ buyers know about the illicit origins of the antiquities they buy, and how do they deal with suspicious information, or ‘red flags’, about illicit origin in their acts of purchase. As well as the direct parties to the sale contract, we have already observed that there can be a range of other legitimate actors providing knowing or inadvertent support to the illicit trade in antiquities, including valuers and appraisers, authenticators, and academics who add value to objects by studying and publishing their history, or translating text inscribed on the objects. In this chapter, we consider these directly and indirectly involved groups of actors, aiming both to clarify the nature and importance of their participation in the licit and illicit parts of the trade, and to theorise that participation as a form of white-collar crime. In this task, criminological studies of white-collar crime are drawn on to develop an analytical frame of reference for engaging with these questions around participation and facilitation, and policy implications considered.