There are totally legal things you can buy which, if revealed publically, can cause someone massive negative harm. Which means a significant percentage of peopl

There are totally legal things you can buy which, if revealed publically, can cause someone massive negative harm. Which means a significant percentage of people will be willing to pay to keep them a secret. Any site which stores these details is now open to attack, since their database is worth money. Some specific examples: * Someone who is publicly seen as an evangelical Christian buying Richard Dawkins books. * A closeted gay person buying any pro-LGBT book/film. * A woman buying sex toys. * An elementary school teacher who buys pornography. * Almost absolutely medical thing. (Think of a blackmail opportunities from the calendar of a therapist or their notes). If websites/shops don't store this data, then their database is worth much less.