Abstract
On-line communities are virtual environments where users exchange contents. Occasionally, users' interactions lead to frictions, jeopardising the proper functioning of the community. Trying to avoid frictions, on-line communities typically incorporate a regulation mechanism based on (i) norms set by the owner of the community; and (ii) human moderators. In this paper we present a participatory legislation mechanism that automatically synthesises norms for an on-line community based on users' complaints about contents. With this aim, we present an agent-based simulator to model the interactions within on-line communities. We then exploit IRON, an automatic norm synthesis mechanism, to regulate simulated on-line communities. As a result, IRON synthesises norms that prevent a user from uploading contents that users regard as unacceptable by means of complaints, hence avoiding frictions.