To be more precise (and Geek Factor 5) the BGP routes serving Facebook's authoritative DNS were withdrawn, rendering all Facebook domains inaccessible. That's per @DougMadory , who knows a few things about BGP/DNS.
Confirmed: The DNS records that tell systems how to find https://t.co/qHzVq2Mr4E or https://t.co/JoIPxXI9GI got withdrawn this morning from the global routing tables. Can you imagine working at FB right now, when your email no longer works & all your internal FB-based tools fail?
An Instagram & WhatsApp outage was the reminder I needed to come back on Twitter. There is so much value here and this feels like a time travel back to 2010! #whatsappdown