People are right to question Investment group Blackstone's acquisition of Ancestry and ask what their motives for DNA database that came with it are. They state a plan to make back the $4.7 billion acquisition price via increased subscriptions, and maybe they will. But there are also huge sums to be made from the DNA database, though Blackstone state they will not be accessing this data nor sharing it with their other companies (they have stakes in drugmakers, insurers and research labs).
Widespread population DNA testing and databases hold a multitude of ethical problems and caution is needed, but I fear it is like trying to hold back the tide and we'll see exponential growth of these.