But the reduction in footfall itself also has cascading consequences. It’s pretty obvious that many US malls are anchored by large retailers that could very easily now go out of business, and then the other retailers in that mall that might have though they were OK now aren’t - and then the mall itself goes as well. That purchasing won’t automatically go to those retailers’ websites, and it might also go to entirely different categories. If you change the channel then you change what gets bought. 

Online advertising is now worth perhaps $250bn, but advertising in total is $500bn and all global marketing is closer to $1tr. Telling people about things they might like or be interested has value, and it isn’t actually evil a priori, but if you can’t ‘track’ people across the web anymore, how do you do that? And how do you reconcile that with wanting more competition to Google or Amazon? I hope that the answer is not that the only companies that can do interest-based ads are Google and Facebook on one hand and brands with their own huge audiences and data such as the Guardian or New York Times on the other. Will one or other of the various industry data initiatives work? Will Apple try a generalised identity or interest platform? I don’t know, but I do know that a trillion dollar industry is up in the air.