We present Ubinion, a service that utilizes large public interactive displays to enable young people to give personalized feedback on municipal issues to local youth workers. It also facilitates discussion and sharing the feedback online using modern social networking services. We present the motivation and rationale behind Ubinion and analyze the results from three large-scale user trials conducted in authentic settings. The evaluation shows that young users are positive about adopting Ubinion, and that they quickly appropriated its use to provide feedback outside the intended scope of the system, but still reflecting their concerns. We argue that Ubinion’s design as a fun and informal tool is appropriate for its purpose, and discuss the versatility of public interactive displays as a municipal feedback medium and as content sources for online communities in general.