The sites may be illegal, but are not blocked. There are plenty of people who still gamble online from the US through off-shore accounts and using off-shore websites.
Yes, online gabling is mostly illegal, thus my "minor exceptions".
But all types of porn except child porn are allowed as far as I know. Definitely all types of anti-government websites are allowed. The first amendment confers very strong protection on free speech.
This Chinese news release is trying to mislead. I think the average Chinese citizen would be shocked to learn the level of freedom of expression and access to information in the US.
But the websites of offshore gambling sites aren't blocked at the national border; it is the transaction, rather than publishing information, which is illegal.
(Apparently, the state of Kentucky has recently tried to seize gambling-related domain names held by remote entities, but that's a new local enforcement tactic which may not endure.)
There are also lots of laws about fraud. Imagine if a Chinese company came to the U.S. making fraudulent claims about its products. We'd condemn them, yet we applaud Google. I don't understand.