Large Online Social Footprints--An Emerging Threat

We study large online social footprints by collecting data on 13,990 active users. After parsing data from 10 of the 15 most popular social networking sites, we find that a user with one social network reveals an average of 4.3 personal information fields. For users with over 8 social networks, this average increases to 8.25 fields. We also investigate the ease by which an attacker can reconstruct a person's social network profile. Over 40% of an individual's social footprint can be reconstructed by using a single pseudonym (assuming the attacker guesses the most popular pseudonym), and an attacker can reconstruct 10% to 35% of an individual's social footprint by using the person's name. We also perform an initial investigation of matching profiles using public information in a person's profile.