What’s wrong with the Apple-Google COVID-19 contact tracing scheme

There have recently been several proposals for pseudonymous COVID-19 contact tracing, including from Apple and Google. The UK’s National Health Service (NHS) is working on just such a system and Ross Anderson, Professor of Security Engineering at the University of Cambridge’s Department of Computer Science and Technology, is one of a group of people being consulted on the system’s privacy and security.
How the proposed system from Apple and Google is designed to work:Click for