The Internet offers users many opportunities for communicating and exchanging ideas, but abuse, censorship, and the manipulation of Internet traffic have put free and open communication at risk. Recent estimates suggest that spam constitutes about 95% of all email traffic; hundreds of thousands of online scam domains emerge every day; online social networks may be used to spread propaganda; and more than 60 countries around the world censor Internet traffic. In this talk, I will present approaches that we have developed to preserve free and open communication on the Internet in the face of these threats. First, I will describe the threat of message abuse (e.g., spam) and describe methods we have developed for mitigating it. I will briefly discuss a 13-month study of the network-level behavior of spammers, and present SNARE, a spam filtering system we developed that classifies email messages based on the network-level traffic characteristics of the email messages, rather than their contents. Next, I will turn to information censorship, and describe Collage, a system that circumvents censorship without arousing the suspicion of the censor. Finally, I will discuss the various forms of information manipulation, including the spread of propaganda in social networks and online "filter bubbles." Although it is difficult to prevent all forms of manipulation, our goal is to make it more transparent to users. Towards this goal, I will describe my broader research agenda and plans, which aim to improve Internet transparency for aspects of Internet communication ranging from network performance to social media to search results using the aggregation of data from a wide variety of vantage points.
Nick Feamster is an associate professor in the College of Computing at Georgia Tech. He received his Ph.D. in Computer Science from MIT in 2005, and his S.B. and M.Eng. degrees in Electrical Engineering and Computer Science from MIT in 2000 and 2001, respectively. His research focuses on many aspects of computer networking and networked systems, including the design, measurement, and analysis of network routing protocols, network operations and security, and anonymous communication systems. In December 2008, he received the Presidential Early Career Award for Scientists and Engineers (PECASE) for his contributions to cybersecurity, notably spam filtering. His honors include the Technology Review 35 "Top Young Innovators Under 35" award, a Sloan Research Fellowship, the NSF CAREER award, the IBM Faculty Fellowship, and award papers at SIGCOMM 2006 (network-level behavior of spammers), the NSDI 2005 conference (fault detection in router configuration), Usenix Security 2002 (circumventing web censorship using Infranet), and Usenix Security 2001 (web cookie analysis).