Brian Wong, chief executive of Kiip, a mobile ad firm that has also sold anonymous data from some of the apps it works with, says users give apps permission to use and share their data. “You are receiving these services for free because advertisers are helping monetize and pay for it,” he said, adding, “You would have to be pretty oblivious if you are not aware that this is going on.”

This is the most worrying part for me. The attitude, in fact down right arrogance, that people should be aware of where their data goes when they are not explicitly told. “Expect adverts unless you are told otherwise” is the excuse of the worst type of profiteering, it makes me sick to my stomach to see the attitudes of some tech companies.