Once ‘public space’ was a clear concept. It was a kind democratic medium that could be accessed by everyone, safely and freely available for traffic between people. Now things have changed; thanks to mobile communication systems, we carry our personal space with us like an air bubble, and the public sphere has become a set of subsets. It sucks in a great many individuals who cannot or will not ‘participate’, or who do not have or do not want to have access to  the means that link the individual bubbles.