Have they though? Everybody I know who grew up in China has told me its trivial to bypass restrictions with VPNs
They can do unconditional blocking at any moment and suddenly you can experience Internet blackout. [1]
The censorship from GFW is ever evolving. See the endless cat-and-mouse games yourself. [2][3]
[1] https://github.com/net4people/bbs/issues/511
[2] https://github.com/net4people/bbs/issues?q=is%3Aissue+state%...
Now, if you’re doing something unrelated that the administration doesn’t like, you can expect VPN use to be included in the long list of charges.
That's the standard procedure. But polices in developed areas usually treat them like antragsdelikte(no trial without a complaint).