What interests me, the affected Facebook users that are NOT in the USA.
They get nothing, their government gets nothing... is the US government the only entity who benefits from this decision?
A fine, at least in the US and whether its a traffic fine for speeding, or a fine levied against a person cheating on their income tax, or a against a company convicted of fraud, is not about "someone" getting something.
In general, i's about punishing the offender and creating deterence that will *hopefully* deter further similar unlawful activity by others. Occasionally additional fines are levied to compensate victims. But this doesn't rise to that level.
Does that always work? Of course not. But a $5 Billion fine is not a slap on the wrist and represents a large percentage of FB's net profits and assets.