Content Abuse and Privacy Concerns in Online Social Networks Md Imrul Kayes University of South Florida, [email protected]
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University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 11-16-2015 Content Abuse and Privacy Concerns in Online Social Networks Md Imrul Kayes University of South Florida, [email protected] Follow this and additional works at: http://scholarcommons.usf.edu/etd Part of the Computer Sciences Commons Scholar Commons Citation Kayes, Md Imrul, "Content Abuse and Privacy Concerns in Online Social Networks" (2015). Graduate Theses and Dissertations. http://scholarcommons.usf.edu/etd/5967 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. Content Abuse and Privacy Concerns in Online Social Networks by Md Imrul Kayes A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Computer Science and Engineering College of Engineering University of South Florida Major Professor: Adriana Iamnitchi, Ph.D. Swaroop Ghosh, Ph.D. Yao Liu, Ph.D. John Skvoretz, Ph.D. Kingsley A. Reeves, Jr., Ph.D. Date of Approval: October 19, 2015 Keywords: Community Question Answering, Crowdsourcing, User Behavior, Cross-cultural Variations, Contextual Integrity Copyright © 2015, Md Imrul Kayes ! ! DEDICATION To my mother Nasrin Sultana. ! ! ACKNOWLEDGMENTS I would like to take this opportunity to express my heartfelt gratitude to my major professor Dr. Adriana Iamnitchi for her invaluable guidance and support. She has always encouraged me and allowed me to explore new research directions that drove my interests. I extend my gratitude to Dr. Swaroop Ghosh, Dr. Yao Liu, Dr. John Skvoretz, and Dr. Kingsley A. Reeves, Jr., for being a part of my defense committee, and Dr. Lingling Fan for serving as the chair in my doctoral defense. I thank my lab mates during my time in the Distributed Systems Group. Xiang, in particular, was always available for any discussion. Thank you for your opinion and suggestion. I would like to acknowledge Yahoo Labs, Barcelona for the internship and Yahoo Answers dataset. I am thankful to Dr. Nicolas Kourtellis and Dr. Daniele Quercia for their guidance and encouragement during the internship. Lastly, I would like to thank Tanvir, Eftay, Subhranil, Wasie, Subhabrata, Bashar, Reza, Nashid, and Ruhin for giving me emotional and practical support during my doctoral studies. ! TABLE OF CONTENTS LIST OF TABLES ......................................................................................................................... iv LIST OF FIGURES .........................................................................................................................v ABSTRACT ................................................................................................................................... ix CHAPTER 1: INTRODUCTION ....................................................................................................1 1.1 Abuse and Privacy in Social Networks ..........................................................................2 1.2 Research Questions ........................................................................................................5 1.3 Contributions .................................................................................................................7 1.4 Outline ............................................................................................................................9 CHAPTER 2: RELATED WORK .................................................................................................11 2.1 Community Question Answering (CQA) Social Networks .........................................11 2.2 Relationships Between Privacy Concerns and User Behavior in OSNs ......................13 2.3 Cultures in Social Networks ........................................................................................14 2.4 Access Control Mechanisms in OSNs .........................................................................15 CHAPTER 3: DATASET: YAHOO ANSWERS .........................................................................19 3.1 The Platform ................................................................................................................19 3.2 Dataset ..........................................................................................................................22 CHAPTER 4: THE SOCIAL WORLD OF CONTENT ABUSERS IN COMMUNITY QUESTION ANSWERING SOCIAL NETWORKS ..............................................................24 4.1 Flags in Yahoo Answers: a Proxy for Content Abuse? ...............................................26 4.1.1 Abuse Reports ...............................................................................................26 4.1.2 Deviance Score .............................................................................................29 4.1.3 Deviance Score vs. Suspension .....................................................................31 4.2 Deviant vs. Suspended Users .......................................................................................33 4.2.1 Deviance is Engaging ...................................................................................33 4.2.2 Deviance is Noisy .........................................................................................35 4.2.3 Deviance is Everywhere ...............................................................................36 4.2.4 Centrality of Suspended Users ......................................................................38 4.2.5 The Suspended but Not Flagged Users .........................................................39 4.3 Social Network Analysis ..............................................................................................40 4.3.1 Out of Sight, Out of Mind .............................................................................40 4.3.2 Birds of a Feather Flock Together ................................................................44 i 4.4 The Good Guys ............................................................................................................46 4.5 Suspended User Prediction ..........................................................................................50 4.5.1 Features for Classification ............................................................................50 4.5.2 Experimental Setup and Classification .........................................................52 4.5.3 Classification Results and Evaluation ...........................................................52 4.6 Summary and Discussions ...........................................................................................53 CHAPTER 5: PRIVACY CONCERNS VS. USER BEHAVIOR IN COMMUNITY QUESTION ANSWERING SOCIAL NETWORKS ..............................................................59 5.1 Privacy Settings in YA ..................................................................................................60 5.2 Results ..........................................................................................................................63 5.2.1 Privacy and Retention ...................................................................................63 5.2.2 Privacy and Social Circles ............................................................................63 5.2.3 Privacy and Accomplishments ......................................................................65 5.2.4 Privacy and Best Answer Quality .................................................................67 5.2.5 Privacy and Abuse Reporting .......................................................................70 5.2.6 Privacy and Deviance ...................................................................................71 5.3 Summary and Discussions ...........................................................................................74 CHAPTER 6: CULTURES IN COMMUNITY QUESTION ANSWERING SOCIAL NETWORKS ...........................................................................................................................76 6.1 Data Preparation ...........................................................................................................78 6.2 Levine’s Pace of Life ...................................................................................................79 6.3 Hofstede’s Cultural Dimensions ..................................................................................83 6.3.1 Individualism (IDV) ......................................................................................84 6.3.2 Power Distance Index (PDI) .........................................................................90 6.3.3 Uncertainty Avoidance Index (UAI) ............................................................92 6.4 Summary and Discussions ...........................................................................................94 CHAPTER 7: AEGIS: A SEMANTIC IMPLEMENTATION OF PRIVACY AS CONTEXTUAL INTEGRITY IN SOCIAL ECOSYSTEMS .................................................98 7.1 Privacy as Contextual Integrity in Social Ecosystems ...............................................100 7.2 System Model and Architecture .................................................................................102 7.2.1 System Model .............................................................................................102