Facebook is indeed down. This includes their other properties as well such as Instagram, WhatsApp and Occulus. Looks to be a DNS or routing issue (Botched BGP setup).
Read more here… https://news.ycombinator.com/item?id=28748203 and here… https://arstechnica.com/…/facebook-instagram-whatsapp-and-oculus-are-down-heres-what-we-know/
It is why I have continually expressed concerns personally regarding allowing ourselves to collectively entrust too much of our lives singularly on the proprietary services of what is essentially is a single for profit driven entity.