How calls for privacy may upend business for Facebook and Google

People detail their interests and obsessions on Facebook and Google, generating a river of data that could be collected and harnessed for advertising. The companies became very rich. Users seemed happy. Privacy was deemed obsolete, like bloodletting and milkmen.

Now, the consumer surveillance model underlying Facebook and Google’s free services is under siege from users, regulators and legislators on both sides of the Atlantic. 

The recent revelation that Cambridge Analytica, a voter profiling company that had worked with Donald Trump’s presidential campaign, harvested data from 50 million  Facebook users, raised the current uproar, even if the origins lie as far back as