I can tell you, as a guy who worked for five years at the head office of a Canadian bank and sat in focus group meetings with individuals and customers, that many customers don't even share their information with their spouse. Believe me, financial and health information are among the most sensitive information, and people want protection.
In addition, are you aware that in the United States there is the American data privacy and protection act going through Congress, which does exactly this? It's a bipartisan bill.