andytoshi, what do you think about saving PoS by bouncing checkpoints/blockhashes off reality?
Then you are introducing trust assumptions and new attack vectors. There are no universally trusted parties to provide checkpoints.
You want to know the top of the chain that everyone is using? Check facebook and twitter. Seeing something different in your client? Someone's trolling you ...
And if somebody has hacked Facebook or Twitter? Or put pressure on them from some USG agency? Or has compromised your access to them? Or maybe you just don't trust them because they routinely censor data and besides treat their users as data crops?