Fully regulate? Quite impossible. The government would regulate cryptocurrency partially.
Of course, governments won't be able to regulate everything even when they desperately want to control bitcoin. So it is true that they can only regulate a few things, but the government can't regulate the bitcoin network.
If you deal with p2p and store Bitcoin in a non-custodial wallet like Ledger then how the government would monitor or regulate you?
There are several things that might prevent banned bitcoin users from trading Ledger
[Hardware Wallet] if the government has prohibited it by regulation. Basically every product is subject to the rules and laws of a particular country, so it is always possible for the government to prohibit its circulation.
Meanwhile, I read this one from Ledger, it's one of their ToS.
4. Risks and recommendations -
SourceYou acknowledge that you are fully aware of all applicable laws and technical constraints relating to the proof-of-stake and proof-of-work blockchains, and to the Services. You acknowledge that you have been warned of the following associated risks and advised of the following recommendations:
4.1 Regulatory changes. Blockchain technologies and related services are subject to continuous regulatory changes and scrutiny around the world, including but not limited to anti-money laundering and financial regulations. You acknowledge that certain Services, including their availability, could be impacted by one or more regulatory requirements.
I just agree the government has ways of preventing you from using bitcoin, monitoring your transactions and such. But I don't think they will succeed in preventing all of them and I agree that the government can only partially regulate it.