How about this for a challenge. Suppose you pay car insurance according to where you drive, as tracked every second by GPS - see here. On the other hand, Transport For London (TFL) conclude that satellite tracking is not accurate enough to charge users according to where they drive - see the report. The best results that TFL could get involve an error rate of 0.86%. So if your insurer mischarges you, how do you argue your case? Or put another way, if a customer disputes the data, how will the insurer be able to demonstrate its billing is completely reliable?