Always read the fine print
People always forget to read the fine print, and then resort to shouting, yelling and complain forums when they find themselves stuck.
Aside from transparency, and clear opt-in opt-out solutions for users, Phorm and BT Webwise have excellent privacy policies, if people would just care to read them:
http://www.phorm.com/about/faq.php?_faqs=23,24,25,26,27,28,29,42,43,44#privacy
In addition, they aim to improve our lives by eliminating the irrelevant adverts that annoy us and replace them with items of actual interest. Doesn't sound too bad to me.
Pity NebuAd in the US is still foundering in a sea of misunderstanding.