This document introduces the UrbanIxD SIG (Special Interest Group) which focuses on designing human interactions in networked cities. The SIG aims to raise interest in urban interaction design, provide a forum for researchers, and build a community. It discusses how urbanization and internet access are growing trends, and how this impacts issues like privacy and data ownership with increasingly integrated urban technologies. The SIG is working to identify future research directions through an exhibition using critical design scenarios to provoke debate around how this domain could develop. It is also hosting a summer school in Croatia in August 2013.