As anyone in China, Estonia, and yeah the US could tell you is that country-wide firewalls are possible. NATs only know how to do "internal" to "external" communication. Especially if you own the communication avenues. So, while ATT, and other networks in the US have their "mini internets" connected to the global network, Russia could easily have implemented a country-wide firewall preparing it to cut itself off. Social media is not just Facebook. China has "internal" social medias, so why can't Russia. So, it may not NEED the external world anymore, but it can connect to it if desired. So they can have it both ways.