How does the block work on a technical level? Did they just nicely ask Facebook to geo-IP block their whole country, and Facebook agreed voluntarily? Is there

How does the block work on a technical level? Did they just nicely ask Facebook to geo-IP block their whole country, and Facebook agreed voluntarily? Is there some legal process, where Facebook's under threat of having money/property in the country seized and/or employees in the country arrested if they don't comply? Or are they doing it without Facebook's assistance? Do they have government-controlled routers that can blackhole specific DNS queries or IP address ranges? Or put their ISP's under threat of some legal process to implement the same? How do we make the Internet more robust against the specific attack launched by the government? Or should governments always be able to shut down sites they don't like, when they judge it necessary?