1) Social computing (SC) such as social networks, blogs, and wikis have seen explosive growth and now over 50% of internet users engage with these technologies. 2) SC is important for research and policy because it impacts economies, societies, and politics. However, Europe lags behind the US in supplying SC applications and supporting innovation in the field. 3) Key impacts of SC include economic and business model disruption, changes to social behaviors, and opportunities for more transparent and engaged governance. SC poses challenges and opportunities for European policymakers seeking to encourage participation and innovation.