when such gaints can run into a problem, what makes you think they can't be shut down ?
LONG LIVE BTC, 100% UPTIME

Facebook, Instagram, Whatsapp Are Down, But Bitcoin is as strong as ever just because of the difference between platforms and technology used.
Facebook, Instagram, Whatsapp are mainly connected to the main server, which leads these services towards centralization, But while considering Bitcoin technology and platform it gives completely innovative solutions.
Bitcoin is completely standalone from other third-party services, rather it's an invention.
Bitcoins is purely based on the peer-to-peer network which is connected to the nearest node to get the latest updated data copy, which verified and securely stored by other nodes. These nodes are independent entities which carry whole data of blockchain within themselves.