How “sensitive” is facebook user data though? All content in a facebook account is already visible to an average of >100 people - their facebook friends.
(Messenger had stronger protections than OP is describing)
Extremely sensitive, by the lights of the organization I work for. The people to whom FB user data is visible are known to the user. Those people have been explicitly authorized by the user to view that data. FB is acting as the user's agent in conveying that data only to authorized recipients, who the user presumably trusts to some degree or another to not further propagate the data. The data is generally not publicly visible, and FB employees are generally not among the list of entities the user intends to convey the data to.
