I think there is a kind of paranoid vanity in some people, the population of the UK is over 67 million 12.4 million of them are children, why would anyone one to track anyone of them except is they were suspected of criminal activity other than that they are not that interested in individuals, the shops use the data for lots of reasons and most of it is anonymous, if I pay by card the business claims the money from my bank account they don't have open access to all my details nor is there an individual record of what I have purchased (unless I have used a loyalty card)