WhACKY! - What anyone could know about you from Twitter

Twitter is a popular micro-blogging website which allows users to post 140-character limit messages called tweets. We demonstrate a cheap and elegant solution - WhACKY! - to harness the multi-source information from tweets to link Twitter profiles across other external services. In particular, we exploit activity feed sharing patterns to map Twitter profiles to their corresponding external service accounts using publicly available APIs. We illustrate a proof-of-concept by mapping 69,496 Twitter profiles to at least one of the five popular external services : Flickr (photo-sharing service), Foursquare (location-based service), YouTube (video-sharing service), Facebook (a popular social network) and LastFM (music-sharing service). We evaluate our solution against a commercial social identity mapping service - FlipTop - and demonstrate the efficiency of our approach. WhACKY! guarantees that the mapped profiles are 100% true-positive and helps quantify the unintended leakage of Personally Identifiable Information (PII) attributes. During the process, WhACKY! is also able to detect duplicate Twitter profiles connected to multiple external services.We also develop a web application based on WhACKY!1 for perusal by Twitterers which can help them better understand unintended leakage of their PII.