Mining Anonymity: Identifying Sensitive Accounts on Twitter
We explore the feasibility of automatically finding accounts that publish
sensitive content on Twitter. One natural approach to this problem is to first
create a list of sensitive keywords, and then identify Twitter accounts that
use these words in their tweets. But such an approach may overlook sensitive
accounts that are not covered by the subjective choice of keywords. In this
paper, we instead explore finding sensitive accounts by examining the
percentage of anonymous and identifiable followers the accounts have. This
approach is motivated by an earlier study showing that sensitive accounts
typically have a large percentage of anonymous followers and a small percentage
of identifiable followers.
To this end, we first considered the problem of automatically determining if
a Twitter account is anonymous or identifiable. We find that simple techniques,
such as checking for name-list membership, perform poorly. We designed a
machine learning classifier that classifies accounts as anonymous or
identifiable. We then classified an account as sensitive based on the
percentages of anonymous and identifiable followers the account has. We applied
our approach to approximately 100,000 accounts with 404 million active
followers. The approach uncovered accounts that were sensitive for a diverse
number of reasons. These accounts span across varied themes, including those
that are not commonly proposed as sensitive or those that relate to socially
stigmatized topics. To validate our approach, we applied Latent Dirichlet
Allocation (LDA) topic analysis to the tweets in the detected sensitive and
non-sensitive accounts. LDA showed that the sensitive and non-sensitive
accounts obtained from the methodology are tweeting about distinctly different
topics. Our results show that it is indeed possible to objectively identify
sensitive accounts at the scale of Twitter.