In TFA: "Also, .US domains are only supposed to be available to U.S. citizens and to those who can demonstrate that they have a physical presence in the United States."

... and ...

"Under NTIA regulations, the administrator of the .US registry must take certain steps to verify that their customers actually reside in the United States, or own organizations based in the U.S. But Interisle found that whatever GoDaddy was doing to manage that vetting process wasn’t working."