. Nielsen, Critical Mass -Worldwide State of the Mobile Web, Nielsen Mobile, 2008.

. Nielsen, Global Faces and Networked Places -A Nielsen report on Social Networking's New Global Footprint, Nielsen, 2009.

K. Liesebach and T. Scherner, D2.4 Requirements. Public Deliverable of EU Project PICOS. Available at www.picos-project, 2008.

R. Hoegg, Overview of business models for Web 2.0 communities, Proceedings of Workshop 'Gemeinschaften in Neuen Medien', TUDPress, pp.33-49, 2006.

C. Clavedetscher, Point: User Involvement Key to Success, pp.30-32, 1998.

J. Rumbaugh, Getting Started: Using Use Cases To Capture Requirements, Object- Oriented Programming Journal, vol.7, issue.5, pp.8-12, 1994.

K. Holzblatt and K. R. Beyer, Requirements gathering: the human factor, Communications of the ACM, vol.38, issue.5, pp.31-32, 1995.
DOI : 10.1145/203356.203361

R. Arlinghaus, T. Mehner, and C. , Reconciling traditional inland fisheries management and sustainability in industrialized countries, with emphasis on Europe, Fish and Fisheries, vol.13, issue.6, pp.261-316, 2002.
DOI : 10.1016/S0169-2046(00)00147-X

/. Pin and P. Shan-chen, The Entity Relationship Model, Toward a unified View of Data, In: ACM Transactions on Database Systems, vol.1, issue.1, pp.9-36, 1976.

F. B. Vernadat, Enterprise Modeling Languages, Proceedings of International Conference on Enterprise Integration Modeling Technology, 1997.

G. Müller and S. Wohlgemuth, Study on Mobile Identity Management, Public Deliverable of EU Project FIDIS, 2005.

M. Hansen, P. Berlich, J. Camenisch, S. Clauß, A. Pfitzmann et al., Privacy-enhancing identity management, Information Security Technical Report, vol.9, issue.1, pp.35-44, 2004.
DOI : 10.1016/S1363-4127(04)00014-7

M. Chew, D. Balfanz, and B. Laurie, Undermining Privacy in Social Networks, Web 2.0 Security and Privacy (in conj. with IEEE Symposium on Security and Privacy), 2008.

F. Adu-oppong, C. K. Gardiner, A. Kapadia, and P. P. Tsang, Social Circles: Tackling Privacy in Social Networks, Proceedings of the 4th Symposium on Usable Privacy and Security (SOUPS '08, 2008.

S. R. Hiltz and K. Passerini, Trust and Privacy Concern Within Social Networking Sites: A comparison of Facebook and MySpace, Proceedings of AMCIS 2007, 2007.

D. M. Boyd and N. B. Ellison, Social Network Sites ? Definition, History and Scholarship, In: Journal of Computer-Mediated Communication, p.13, 2008.

E. Ganglbauer, S. Döbelt, and B. Ueberschär, D7.2a First Community Prototype: Lab and Field Test Report, 2010.