Securing Social Media: A Network Structure Approach

The work described in this thesis has been carried out in the ASCI graduate school. ASCI dissertation series number 282. i Acknowledgments My PhD would not have been possible without many people's contributions along the way. Let me take the opportunity to thank a few who have influenced me in their own fashion. Henk, I owe you a debt of gratitude for giving me the opportunity to do a PhD at TU Delft. You were very generous to turn my request for an internship in September 2007 into a PhD candidacy a year later. Your guidance particularly in the final year was critical and invaluable. While my research work may have been a bit different from your expertise, your comments during our meetings were very insightful. Johan, thank you very much for the freedom you have given me during the last 4 years. Our diverse group of 15-20 researchers you brought together with two large EU projects is something you should be very proud of. I hope that you are instrumental in creating such groups again in the coming years. Naza, you get my special shoutout. Thank you very much for guiding me throughout my PhD, in-person and on-skype. It was only through your invitation to Campina Grande that I had some of the best times in the last 5 years. Writing a paper in the day and attending the carnival in the night was a great combo. Wish Aida, you, and your hospitable family all the very best! Dimitra and Boxun, thank you for inviting me to be your officemate after Naza left. I enjoyed talking to you both about every topic in the world (and alternate universes); and that was everyday. Dimitra, thank you very much for your graph expertise inputs on my ideas. Boxun, I enjoyed our weekly dailywok dinners at 7:45 pm. Wish you both the very best! Mihai, visiting Brazil with you was fun. Rio de Janeiro was possible only with your broken Portuguese. On a different note, given your wit, you should consider writing for The Daily Show or SNL :-) Rahim, I learned tennis much better playing with you than from a coach. I also enjoyed going on a day trip to places like Texel and Brugge. I liked our many dinners at Burgerz with Boxun. Lucia, I enjoyed talking to you be it in the office corridor, Aula or gtalk. I always …