It's not simply just a ledger.

I'm talking about every data point that facebook has, to be hashed and competitively manipulated in a global market place.

Trust is very relative but using a bitcoin-like solution would allow for the market to compete for the better solution, each and every day. Facebook's authoritarian solution won't last forever, nor should it; allowing competition through FB's data could be a way that FB stays in the limelight.