I'm watching the Channel 4 News special about this incident and it seems to me that there is a lot of serious unknowns. But perhaps I am just not up to date on

I'm watching the Channel 4 News special about this incident and it seems to me that there is a lot of serious unknowns. But perhaps I am just not up to date on everything. Has Facebook released information on what data about friends of friends was "stolen" by Cambridge Analytica yet? From what I've seen, Facebook has known about this since 2015, so I assume they have a pretty good idea of this.