Social networks have changed our daily life and they have the potential to significantly influence and support Requirements Engineering (RE) activities. Social network-based RE approaches will allow us to overcome limitations of traditional approaches and allow end users to play a more prominent role in RE. They are key stakeholders in many software projects. However, involving end users is challenging, particularly when they are not within organizational reach. The goal of our work is to increase end user involvement in RE. In this paper we present an approach where we harness a social network to perform RE activities such as elicitation, prioritization and negotiation. Our approach was applied in three studies where students used Facebook to actively participate in RE activities of different projects. Although there are limitations, the results show that a popular social network site can support distributed RE.