As much as it blows the minds of many who know little about China. China isn't North Korea. There aren't secret police running around tapping your phones and WeChat (I guess it's not like the US either).

You can talk openly about pretty much anything within reason. Sure if you tell people: "I'm planning a rebellion against the state and I have a shipment of weapons due from Pakistan" then you might have issues. But I think the same applies to any country.

The only thing you can't do is promote it to wider audiance through the media. That's a no no.