authority:
the network and coin has no jurisdiction so cannot be controlled... only businesses with a registered address are restricted by laws of that jurisdiction
Even if Bitcoin is beyond national jurisdiction, it can still be controlled on an international level through relevant international organizations such the UN or IMF, which are established to address global scale issues. As I see it, international treaties are meant to specifically regulate issues regarding the global commons. Anyways, there shouldn't be any real difficulty to control Bitcoin worldwide if it were worth the effort and such a need arose.
How?
the IMF can only deal with government money. EG a painting or jewellery is a tradable asset. the IMF wont get involved with that
the UN can only deal with governments.
though governments can make laws to prohibit (make illegal to use) something. the law is just paper. paper cannot attack electric. just like paper couldnt directly attack liquid (moonshine/alcohol of the last century)
it requires court orders and law enforcement (HUMANS) to investigate and deliver these bits of paper to ISP's to shut off the internet of <6000 nodes/raid pubs/bars and drinking clubs.
but bitcoin nodes are not (should not) be confined to one country. thus if america prohibits bitcoin and gets a court order to disconnect the internet of 1500 peoples landlines. there are still 3700 nodes connected to the internet in other countries.
right now there are 91 countries that have nodes running. so all 91 countries will need to pass a law to prohibit bitcoin to then use that to all simultaneously get the ISP's of all nodes to disconnect the internet of all <6000 nodes.
though in minutes someone can knock on a neighbours door and borrow their landline internet or a open wifi to get their node online, while they sort out their own landline.
bitcoin is a little weak in this area because it does not cover all 200 countries and the majority are not using satalite internet to avoid a small possibility of international law changes and/or ISP take down requests.
but even in a worse case. people will just change their home address to get access to a new landline access to the internet. and borrow/rent friends internet for a month, while its getting sorted. thus all they can do is disrupt bitcoin temporarily, thus its a fools errand to take down someones internet.
mining pools already have several servers to mitigate the risk of not relying on one ISP access to the internet. so overall i cannot see governments being able to permanently stop the bitcoin network. but we should atleast not be apathetic and not trust/hope governments wont change laws or isps wont follow court orders or pretend that 91 countries is enough diversity/distribution.
we should always be looking to expand diversity/distribution to mitigate risks.