Collective intelligence is the surprising result of collaborative endeavour with only light rules of co-ordination that lead to the emergence of large-scale, coherent resources (such as Wikipedia). The existence and stability of these resources present major challenges for all the researchers engaged in Web Science. How, from a technical point of view, can collective intelligence be enabled? What are the socio-economic reasons why individuals participate in collective endeavour? What legal framework governs (or should govern) the resources that are created? What is the psychology of identification with an online collective community? How can collective intelligence emerge, given the different languages used by different genders, races, classes and communities? What role is there for policy-makers to engage in and facilitate collaborative endeavour? In an age where political participation is declining, harnessing the potential of collective and collaborative intelligence is an important theme for governments as they try to engage citizens, verify their legitimacy and find creative policy levers.