[m0v_eax]

Because people expect services as robust and useful as Facebook to be free? Based on how much time people spend using their service, the user's data is hardly a large price to pay. Have certain types of things you like, profession, education, gender, demographic and expect your profile able to be targeted (anonymously) with advertising. Share something public (including anything above), expect any corporation to be able to see or mine it.

[braythwayt]

I think your comment is in line with mine. Many people think they are making a trade-off: The use of the service in exchange for data that corporations can mine.

Some even consider this a win-win, as they believe that they will receive advertising for things they may actually want to buy.

However, not everybody expects the data to be shared with other users of the service. This is why I suggested that this may be an unexpected escalation of expectations. Facebook is quite transparent about sharing your data with advertisers.

It is less transparent about sharing your data with other individuals.

[Natanael_L]

And how do you explain shadow profiles?