I suspect the Great Firewall already does whitelisting rather than blacklisting. When an external (out of china) domain is visited from within china (for the f

I suspect the Great Firewall already does whitelisting rather than blacklisting. When an external (out of china) domain is visited from within china (for the first time), it is blocked. It is then later unblocked. I've experimented with this a few times, and it always happens like that.