Also sometimes called “laboratories of ideas,” think tanks have attracted a growing attention from scholars as they are increasingly visible in the public space. They have often been studied within a national framework, without a single universal definition. However, their relations with public authorities, with the academic field and with the media (including the European media) vary and deserve analysis on a case-by-case basis. The same applies to the uses of the term “think tank”, which involve strategies of positioning and of legitimization.