  The internet can be broadly divided into three parts: surface, deep and dark.
The dark web has become notorious in the media for being a hidden part of the
web where all manner of illegal activities take place. This review investigates
how the dark web is being utilised with an emphasis on cybercrime, and how law
enforcement plays the role of its adversary. The review describes these hidden
spaces, sheds light on their history, the activities that they harbour
including cybercrime, the nature of attention they receive, and methodologies
employed by law enforcement in an attempt to defeat their purpose. More
importantly, it is argued that these spaces should be considered a phenomenon
and not an isolated occurrence to be taken as merely a natural consequence of
technology. This paper contributes to the area of dark web research by serving
as a reference document and by proposing a research agenda.
