In Australia, I’ve been told the government saves all text messages sent, although they are not allowed to view the contents of those messages due to privacy reasons.

The government in China may seem to censor a minority of what people say, and it may seem to be a breach of peoples basic human rights, but they do it to ensure that the majority of the people can live in a somewhat peaceful society. Seeing as there are so many inhabitants in China, were they all to be allowed to say/do whatever they’d pleased, it could turn into chaos. Religion and beliefs will clash, groups using violence against the government which ultimately leads to more blood being shed.

Least thats my view of a ‘possible’ scenario.

The real problem is that many people never register their phone numbers, the govt has no way of knowing my phone number, unless they call me or someone I've called that is.

Anyway, I'd go more with an enrollable system, auto tests messages you receive, unless you opt out.

Perhaps most people don't want those messages, but some may.
Then again, no matter what you say about rules and such in China, I still feel free'er and happier living here than Australia.