Chances are, your landing pages undergo heavier scrutiny than your Privacy Policy or Terms of Use. But even if you're not paying attention to the language contained in these documents, website visitors, privacy advocates, and government agencies are.
Facebook felt the heat twice in 2009; first in February when they changed their Terms of Use, and later when they introduced new privacy settings that the Electronic Privacy Information Center charges will "violate user expectations, diminish user privacy, and contradict Facebook's own representations."
More recently, the Federal Trade Commission launched a series of roundtable events to debate online privacy regulation, and flexed their muscle with the "FTC Guides Concerning the Use of Endorsements and Testimonials in Advertising."