> And as far I know, if you go there with roaming ON with your phone, these social networks still work as well. That's because roaming phone traffic is routed

> And as far I know, if you go there with roaming ON with your phone, these social networks still work as well. That's because roaming phone traffic is routed through your home carrier, through whatever telephone traffic peering agreement the phone companies have. If a Chinese person roams to the US using a Chinese cell phone plan, it works in the other direction. So their phone is still behind the great firewall even though they're physically outside of China.