The rivalry between Google and Facebook in 2011 crystallized around a specific and revealing dispute: contact data. When Facebook launched a feature encouraging users to import their Gmail contact lists, Google responded by blocking the export — citing, with some irony, Facebook's own policy of refusing to allow users to export their Facebook contact data to competing services.

The episode illustrated a principle that technology companies prefer not to state directly: data is power, and the companies accumulating the most of it are increasingly unwilling to share it in ways that might strengthen competitors. Google had spent years building a comprehensive picture of its users' relationships through Gmail. Facebook had spent years building a different but overlapping picture through the social graph. Each company's data was valuable precisely because it was exclusive.

Google's move was widely interpreted as a retaliatory shot in a war that was just beginning to become visible to consumers. The search giant had watched Facebook grow from a college networking site into a platform that was capturing meaningful amounts of time and attention that might otherwise have been spent on Google properties. More troubling, Facebook was developing a rich, personal model of user identity that threatened to compete with Google's ability to target advertising.

The contact export dispute was ultimately resolved through negotiation, with both companies making modest concessions. But the underlying tension — two companies with enormous data repositories, each wanting access to the other's while protecting its own — has only deepened in subsequent years as the data economy has become more explicitly central to both companies' business models.

Users caught between these corporate interests have limited options. The data they generate belongs, under current legal frameworks, primarily to the platforms that collect it. The dispute over who gets to use it is, at its core, a dispute conducted on terms that the users themselves have no formal standing to influence.