From Josh Bernoff:
In a survey of 37,000 US and Canadian online adults, we first asked how concerned people were with companies accessing their personal information. More than 70% were concerned about social security numbers and credit cards. Less than half cared about their phone number, and only 19% were concerned about their online reviews. This proves people are at least thoughtful, and distinguish between extremely sensitive information and other information.
Marketers -- especially direct marketers -- love data. But now, over 15 years into the Web, consumers are becoming far more aware of how data collection can go awry, and are voting with their pocketbooks. You can collect and use this data broadly and hope you don't run afoul of an angry consumer with a lot of Twitter followers ready to destroy your brand with your own behavior.