  The community deception problem is about how to hide a target community C
from community detection algorithms. The need for deception emerges whenever a
group of entities (e.g., activists, police enforcements) want to cooperate
while concealing their existence as a community. In this paper we introduce and
formalize the community deception problem. To solve this problem, we describe
algorithms that carefully rewire the connections of C's members. We
experimentally show how several existing community detection algorithms can be
deceived, and quantify the level of deception by introducing a deception score.
We believe that our study is intriguing since, while showing how deception can
be realized it raises awareness for the design of novel detection algorithms
robust to deception techniques.
