According to court documents originally filed last April and finally unsealed on March 23, Netflix and Facebook "enjoyed a special relationship" for "bespoke access" to user data, which Netflix paid over $100 million for.

According to the filing:

By 2013, Netflix had begun entering into a series of "Facebook Extended API" agreements, including a so-called 'Inbox API' agreement that allowed Netflix programmatic access to Facebook's user's private message inboxes, in exchange for which Netflix would "provide to FB a written report every two weeks that shows daily counts of recommendation sends and recipient clicks by interface, initiation surface, and/or implementation variant (e.g., Facebook vs. non-Facebook recommendation recipients).

In August 2013, Facebook provided Netflix with access to its so-called "Titan API," a private API that allowed a whitelisted partner to access, among other things, Facebook user's "messaging app and non-app friends."

The anti-trust class-action lawsuit was filed by two UC citizens, Maximilian Klein and Sarah Grabert, who claim that the two Silicon Valley behemoths agreed to "custom partnerships and integrations that helped supercharge Facebook's ad targeting and ranking models" from at least 2011 stemming from the personal relationship between Mark Zuckerberg and Netflix co-founder Reed Hastings.

"Within a month" of Hastings joining Facebook's board, the two companies signed an "Inbox API" (Application Programming Interface) which allowed Netflix "programmatic access to Facebook's user's private message inboxes," the Daily Mail reports.