Xiaodong Jiang Jason I. Hong James A. Landay Approximate Information Flows: Socially-Based Modeling of Privacy in Ubiquitous Computing. 176-193 2002 conf/huc/2002 Ubicomp http://link.springer.de/link/service/series/0558/bibs/2498/24980176.htm db/conf/huc/ubicomp2002.html#JiangHL02