Data is one of the best tools we have for fighting the Covid-19 outbreak, but right now health data — like consumer data — is held in silos in many different institutions and companies. And while third parties can track, trade, and negotiate that data, the people who create it and who have the biggest stake in it, are often cut out of the deal. Their virtual self doesn’t belong to them, which creates problems of access, security, privacy, monetization, and advocacy.Blockchain can be used to solve these issues, by putting individuals in control of their data, which would be encrypted and and stored in a distributed network that no entity owned. Putting people in control of their data, and their health data in particular, would allow them to control who has access to it, and what they’re allowed to do with it. It would also allow secure sharing of data for critical public health purposes, such as contract tracing, without compromising privacy. It’s time that we reclaim our data as an asset that we create, and which we should both control and benefit from. Healthcare data is a perfect place to start.