Supposing one law or another was passed giving the US govt the power to block offending domains, if push came to shove couldn't the US government ultimately block any domain anywhere via control over the .NET TLD of ROOT-SERVERS.NET and GTLD-SERVERS.NET? e.g. punish/block any nameserver allowing thepiratebay.se to resolve to it's real IP
The way I understand it, who controls the root servers can take down .se as a whole, but not individual .se domains.
If the US would take down .se as a whole, big diplomatic issues would arise immediately, with the end result of either removing root server control from the US or a split of the domain system (between the US and an opposing global entity). But even then, as long as people inside Sweden have their computer pointed up to their ISP dns server which in turn has it pointed to the .se dns server, turning off .se in the root server would not stop swedish people from using swedish sites without any interruption.
They can easily, legally block things in the USA for USA ISPs.
They risk sparking a diplomatic incident if they were to try to take down a .ccTLD domain. Non-USA based root servers would not have to abide by USA rules, and in fact, local websites might get court injunctions to force ISPs to continue to resolve example.xx into what ever was there before. This means whether a domain resolves depends on what DNS servers you talk to.
What your describing might fragment the DNS system into multiple different ones.
This isn't about blocking domains, this is about the DHS or FBI seizing the domain, which they can only do with TLDs whose registrar is located in the US (.com, .net, .org, .us, amongst others)
It's not the registrar but the registry (Verisign) they go to. Lots of people switched from GoDaddy to Gandi last month, a French registrar, but that won't help against this .. problem.
Sorry, my bad. I'm not that familiar with the specific terminology, so I tend to confuse some things. A better formulation would have been "TLDs which are based in the US".