  The currently deployed contact-tracing mobile apps have failed as an
efficient solution in the context of the COVID-19 pandemic. None of them has
managed to attract the number of active users required to achieve an efficient
operation. This urges the research community to re-open the debate and explore
new avenues that lead to efficient contact-tracing solutions. This paper
contributes to this debate with an alternative contact-tracing solution that
leverages already available geolocation information owned by BigTech companies
with very large penetration rates in most countries adopting contact-tracing
mobile apps. Moreover, our solution provides sufficient privacy guarantees to
protect the identity of infected users as well as precluding Health Authorities
from obtaining the contact graph from individuals.
