Abstract:
Twitter is a popular micro-blogging website which allows users to post 140-character limit mes-
sages called tweets. Twitter users (also called Twitterers) post activity messages about their
daily lives, opinions on current events and news, and even have conversations with other users.
In addition, Twitterers also share various other information like photographs, videos and visited
locations hosted on other external services like Flickr, YouTube and Foursquare. Therefore,
tweets contain variety of information obtained from a combination of multiple sources. We
demonstrate a cheap and elegant solution { WhACKY! { to harness this multi-source informa-
tion to link Twitter pro les across other external services. In particular, we exploit activity feed
sharing patterns to map Twitter pro les to their corresponding external service accounts using
publicly available APIs. We illustrate a proof-of-concept by mapping 69,496 Twitter pro les to
at least one of the ve 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 iden-
tity mapping service { FlipTop { and demonstrate the e ciency of our approach. WhACKY!
guarantees that the mapped pro les are 100% true-positive and helps quantify the unintended
leakage of Personally Identi able Information (PII) attributes. During the process, WhACKY!
is also able to detect duplicate Twitter pro les connected to multiple external services.We de-
velop a web application based on WhACKY!1 for perusal by Twitterers which can help them
better understand unintended leakage of their PII.