Consider a hypothetical situation . You go to buy healthlife insurance All Insurance companies have deals with various data brokers if one has , others will have to it ' s their business model to reduce risk as much as possible by knowing as much as possible . So your payment history ends up with them . A Johns Hopkins University study says Home cooking a main ingredient in healthier diet So the insurers ' risk model is written to take that study ' s findings into account . You , with your frequent purchases of restaurant food , are now a riskier proposition You end up with higher premium . Now before you write it off as too much paranoia , consider this a r t i c l e t o p r i c e c a r i n s u rancebasedonfacebookposts Admiral Insurance will analyse the Facebook accounts of firsttime car owners to look for personality traits that are linked to safe driving . For example , individuals who are identified as conscientious and wellorganised will score well . The insurer will examine posts and likes by the Facebook user , although not photos , looking for habits that research shows are linked to these traits . These include writing in short concrete sentences , using lists , and arranging to meet friends at a set time and place , rather than just tonight . In contrast , evidence that the Facebook user might be overconfident such as the use of exclamation marks and the frequent use of always or never rather than maybe will count against them . That project was shelved but that ' s an indication of how eternally persistent digital data can be harmful .