I just posted a link to this Computerworld article on my Twitter feed, but I think it's so important that I have decided to mention it here as well. The article describes the dangers brands are beginning to face with over aggressive big data and data mining practices. The key point is that it's not just about what is legal, but that consumers are can also be sensitive to what they view as privacy violations and over aggressive marketing.
These are extra legal areas where codes of conduct developed by industry and trade associations have traditionally protected both research agencies and their clients from public backlash. It has become fashionable in some quarters to argue that these quaint notions are holding back market research and providing an opening for new entrants to realign the competitive balance in the industry. This is a good reminder that respect for consumers never goes out of fashion.