I would like to beg to differ!!! I am Cherokee and that's a crock of crap. If they were making these calls to others on their own reservation or within their tribe, or on tribal land, maybe so. However, if they are making calls to citizens throughout the usa, via a federally regulated utility, and they are held accountable as any other Americans to federal law and jurisdiction.
At least that's the way it works with the Cherokee Nation and I doubt that the Sioux Nation has a seperate set of laws that gives them the right to violate everyone elses rights as well as State and Federal law.
Illegal operations such as this HAS ZERO legal ability to do anything. Their illegal threats about serving papers are just that,illegal threats. NO court in the USA wouls even entertain their illegal racket, and in fact IF they did try to take you to court (they never will) they most like likely would be arrested for attemptingto use the courts for illegal extortion.
Just received another call from these crooks. Thanks to a previous posting on this site. I have turned the information over to the TX AGs office. They are researching info as I write.