Now they blame "wrong update of BGP protocol". https://www.theverge.com/2021/10/4/22709260/what-is-bgp-border-gateway-protocol-explainer-internet-facebook-outage

https://en.wikipedia.org/wiki/Border_Gateway_Protocol

https://www.ciscopress.com/articles/article.asp?p=2738462

Remember cyber polygon scenario: malicious update done by hackers.

Why it is important ? In short it is worse than DNS because it is communication layer between internet subnets. And subnets are for example networks of our internet providers.It looks more critical than DNS as DNS are just changing numbers to domains,but BGP is about what way the messages will be sended.

If they would take control over BGP we can be in deep shit if they would like turn it down.

Migrations: probably steganography or other covert communication if they will leave only controlled servers.

Maybe also some anonymous networks,it depends how their routing works. If they plan put their dirty hands on routing protocols it can be problem for all of us.