How open should open data be?

Do you remember life before Citymapper? Thanks to Transport for London opening its data, a new wave of innovative transport apps were made possible. This is just one example of how open data has contributed to our everyday lives financially, socially, culturally and more.
Open data impacts everybody. Through it we can access healthcare services, understand our governments better and, of course, travel to places more easily. But, how open should open data be?
To find the answer for this episode of the Big Questions podcast we visited Sir Nigel Shadbolt, professor at the Department of Computer Science at the University of Oxford, principal at Jesus College and co-founder and chair of the open data institute.