  An average smartphone is equipped with an abundance of sensors to provide a
variety of vital functionalities and conveniences. The data from these sensors
can be collected in order to find trends or discover interesting correlations
in the data but can also be used by nefarious entities for the purpose of
revealing the identity of the persons who generated this data.In this paper, we
seek to identify what types of sensor data can be collected on a smartphone and
which of those types can pose a threat to user privacy by looking into the
hardware capabilities of modern smartphone devices and how smartphone data is
used in the literature. We then summarize some implications that this
information could have on the GDPR.
