I. Introduction
With a continuously growing multitude of available Web Services, the SOC paradigm has become essential for developing Web 2.0 applications. SOC promotes assembling Internet-accessible components, called services, to create new applications. Then, applications can be developed using existing services as the foundations upon which to build, potentially decreasing the cost of the development process. Web Services, the most common technological materialisation of SOC, are very important to the industry because they show functionality/data that can be accessed remotely. Further more, as social networks and Web Service-powered computing paradigms such as Cloud Computing became more popular, new applications which combine Web Services from different sources-or “Web mashups”- emerged [1].