They're Facebook, I'm sure if they actually bothered they would be able to design things so that deleted data could also be removed from backups and expired out

They're Facebook, I'm sure if they actually bothered they would be able to design things so that deleted data could also be removed from backups and expired out of CDN's. I mean hell, at my company we are putting in tools and methods that will allow us to very easily remove data with a single command from our systems should a customer/partner request their data deleted.