  Following Turkey's 2020 decision to revoke border controls, many individuals
journeyed towards the Greek, Bulgarian, and Turkish borders. However, the lack
of verifiable statistics on irregular migration and discrepancies between media
reports and actual migration patterns require further exploration. The
objective of this study is to bridge this knowledge gap by harnessing novel
data sources, specifically mobile phone and Twitter data, to construct
estimators of cross-border mobility and to cultivate a qualitative
comprehension of the unfolding events. By employing a migration diplomacy
framework, we analyse emergent mobility patterns at the border. Our findings
demonstrate the potential of mobile phone data for quantitative metrics and
Twitter data for qualitative understanding. We underscore the ethical
implications of leveraging Big Data, particularly considering the vulnerability
of the population under study. This underscores the imperative for exhaustive
research into the socio-political facets of human mobility, with the aim of
discerning the potentialities, limitations, and risks inherent in these data
sources and their integration. This scholarly endeavour contributes to a more
nuanced understanding of migration dynamics and paves the way for the
formulation of regulations that preclude misuse and oppressive surveillance,
thereby ensuring a more accurate representation of migration realities.
