  In order to provide personalized services to users, Internet-based platforms
collect and utilize user-generated behavioral data. Although the 'stop using my
data' right should be a fundamental data right, which allows individuals to
request their personal data to be no longer utilized by online platforms, the
existing preventive data protection measures (e.g., cryptographic data
elimination, differential privacy) are unfortunately not applicable. This work
aims to develop the first Evidence Generation Framework for deterring
post-acquisition data right violations. We formulated the 'stop using my data'
problem, which captures a vantage facet of the multi-faceted notion of 'right
to be forgotten'. We designed and implemented the first blockchain-assisted
system to generate evidence for deterring the violations of the 'stop using my
data' right. Our system employs a novel two-stage evidence generation protocol
whose efficacy is ensured by a newly proposed Lemma. To validate our framework,
we conducted a case study on recommendation systems with systematic evaluation
experiments using two real-world datasets: the measured success rate exceeds
99%.
