- An open letter, signed by +300 scientists from 25+ countries, concerning an open, transparent, and private-by-design COVID-19 contact tracing system. Centralisation has to be avoided to limit surveillance and repurposing. https://drive.google.com/file/d/1oqg2dxpu-x-rzzetlpv3lfa259nrpk1j/view 18 comments worldnews