It was intentionally "leaked"; the whole thing is a PR move. Facebook's entire business is predicated upon having intimate knowledge of its users and is as such irreconcilable with the concept of privacy.
> This was an internal memo meant for an internal audience to address an internal problem.
Do you actually think this can address "the problem" or is it performance?
HN is predominantly ad-tech or ad-tech related people. It's uncomfortable for them.