1. Social Networks on the Cloud Evimaria Terzi Boston University

2. Social Networks on the Cloud Yesterday at noon....

3. Social Networks on the Cloud?...at midnight....

4. We are all (together) on the cloud Could that be more social? Everything you tweet, facebook, linkedin to....and pretty much everything we do is connected to the cloud...and seems to be working

5. We are all (together) on the cloud Could that be more social? Everything you tweet, facebook, linkedin to....and pretty much everything we do is connected to the cloud and seems to be working. So, are we done?

6. Where I am coming from The world of “simple” problems... (as in simply stated) Which are the “central” nodes in a social network? Whom should I follow on Twitter? Which blogs should I read? Which scientists are central figures in a domain?

7. Where I am coming from The world of “simple” problems... (as in simply stated) What is my centrality in a social network? How central am I on Facebook? How central am I in the scientific community?

8. Centrality Definition: number of information pathways controlled by the nodes Computation: Intensive computational task Enumerating information pathways is demanding

9. Challenges in centrality computations Centrality of nodes and groups of nodes Context-based centrality Centrality of nodes in dynamic graphs

10. Benefits from centrality computations Imagine if...  you knew (and could monitor) your centrality score  you knew (and could monitor) your friends centrality score  you could know the set of central nodes in a network Benefits to:  Individuals  Businesses  News agencies/political campaign designers  Recruiting agencies....

11. Centrality and the Cloud Centrality is computationally-intensive task; cloud can provide computational resources Challenges: efficient execution of such queries number of (concurrent) users dataset sizes evolving graphs

12. Beyond centrality: New types of queries Leverage cloud infrustructure to support social- network-specific queries Centrality Community detection Trend identification

13. Going back to my simple world How can we protect the privacy of social-network users? Anonymity,differential privacy, privacy scores Privacy issues on the cloud All our data is on the cloud All our queries are asked to the cloud Cloud knows everything

14. Privacy-preserving data management on the cloud How can we protect the privacy of social-network users? Anonymity,differential privacy, privacy scores Privacy issues on the cloud All our data is on the cloud All our queries are asked to the cloud Cloud knows everything Opportunities for privacy- preserving data management research

15. Summary Social networks are on the cloud Unresolved issues Leverage the cloud to add more functionalities to social networks (i.e., facilitate new types of queries) Protect the privacy of individuals Unresolved issues are good for a relationship and for researchers

16. One last perspective Cloud provides computing power Social networks have hidden man power How about human computations?