Today's Facebook story is about about how Facebook manipulate its users.
The outrage is understandable in that users don't like the idea of being used as "lab-rats". However, the reaction is symptomatic of the asymmetry of the agreements at the heart of many large services.
Facebook and Google in particular have user agreements that have a simple core concept; you use the service for free and we'll get to collect data.
Most people assume that the data is used for targeted advertising and I'm sure it is... but what else? Staying away from conspiracy theories, the point is that the user does not know. They do not know what information about them is being collected, what is being kept or how the data is used. There is a huge asymmetry, the organisation has all the information and the individual none.
When using these services you don't even get to know what they know. About you.
What Facebook does with all its extra personal information—the data isn't currently allocated to the advertising product—is largely unknown to the public.