China Tech News (CTN) is reporting that if China does make good on its threat to block unregistered domestic websites, it may also affect sites that have registered (via China Digital Times):

About 80% of China’s 660,000 domestic websites are built through renting a virtual host computer which is based on sharing the same IP address and servers. Once a particular Chinese user breaks the rules, many others who share the same IP address and server will be affected.

This currently happens with the Great Firewall, where some overseas sites with clearly innocuous content are not directly accessible in China because they share resources with other sites that the government finds questionable. However, I think it would be more difficult for the state to apply such broad blocking tactics domestically.

The details on the number of sites that have registered isn’t really clear. CTN’s June 17 report notes:

MII says about 30% of websites in China still have not registered
for an Internet Content Provider (ICP) identification number. As a
result, not only will these websites face closure, but they will also
bring risks to others who share the same IP address with them.

That rough estimate is four percentage points lower than the more-definite and widely reported number provided by the ministry 10 days earlier.

Tue Jun  7,10:59 AM ET, AP Shanghai dateline

Private, noncommercial bloggers or Web sites must register the complete
identity of the person responsible for the site, it said. The ministry,
which has set a June 30 deadline for compliance, said 74 percent of all
sites had already registered.

Private estimates had put the percentage of registrations in the first week of June at a much lower number, though the BlogHerald report noted here was referring to bloggers and not websites (individual bloggers using hosting services do not need to individually register). Still, as Fons noted, government statistics are not trustworthy.

"People can come up with statistics to prove
anything. 14% of people know that." - Homer Simpson