Another basic consideration was respecting the privacy
and self-reported data of the participants, and the deletion of
“external” traces belonging to devices not registered for the
particular deployments. Privacy concerns of the participants
were answered by the anonymisation of collected data. Since
privacy issues should not be perceived by the participants
themselves as an afterthought, all were informed prior and
during the experiments regarding the data collection aspects
of their participation, the future availability of the produced
anonymised data sets and our conformance to the related
legislation (EU directive 95/46/EC). At the same time, users
had control over the software components running on their
smartphones and could opt for turning them off anytime.