The large scale.... Well, as all three of today's witnesses pointed out, the intentions of public health surveillance are ones that I think we would all agree with, in that they are trying very hard to track what is happening within the pandemic to see where the virus is spreading in geographical areas and within which population groups and so on. It's a very important task, but the fact that it's an important task doesn't reduce the fact that there are risks entailed in it at every stage: from data collection through to data analysis and the interpretation and use of those data. At every point, there are difficulties.
What I don't think we should be underestimating is the character of those difficulties. Those difficulties also—rather like the simpler sense of surveillance as watching a suspect, for example—involve harms. There are harms at the individual level, but there may also be harms at the group level: questions of equity, questions of justice, questions of how a group is characterized and so on. The question of the scale really just requires that we look at the issues of scale with a view to their being understood and regulated appropriately.