An Internet troll is a person who deliberately upsets users of online forums or social media. The term has been taken up widely in media discourses about democracy and the Web. Internet trolls and the act of ‘trolling’ thus speaks to a renewed significance of monsters and the monstrous in modernizing liberal democracies. Following ideas developed in science and technology studies (STS), monsters have the generative political capacity to teach us about heterogeneity and hybridity. Indeed, trolls have historically been understood not just as dangerous, but also as invitations to try to come to terms with ‘the other’, which cannot be ignored. In this paper, I explore this potential in relation to online trolling. I start by examining the rise of the troll metaphor in relation to online discourse and observe a shift towards an increasingly broad usage. I argue that Internet trolls are no longer only understood as acting for the sake of controversy itself. Today, the designation is also used to demarcate the boundaries of proper debate, i.e., by expanding the label of trolling to include things like information warfare, hate speech, and sometimes even political activism. Using the troll figure in this way invokes and reproduces ideals about deliberative democracy, where an ongoing public debate that meets certain standards of rationality and inclusiveness is understood as central to democratic societies. However, trolls per definition defy such terms, which means that their subversive political potential as monsters is contained rather than exploited in this frame. With the help of Belgian philosopher of science Isabelle Stengers’ use of the figure of the idiot, I suggest that to enter into a more interesting relationship with online trolls, we may have to open for the possibility that ‘there is something more important’, which is not articulated ‘seriously’, but is nevertheless crucial for the sort of issue-oriented take on democratic politics currently being developed in STS. More specifically, online trolling may be politically generative in the sense that trolls challenge the dichotomy between serious ‘public’ issues and ‘private’ jesting.