I wonder what kind of trouble US Digital got themselves into. Today I
received a letter from them saying I needed to sign it agreeing to obey the
law in several different ways, or they wouldn't sell to me anymore. My
first thought is somehow they get themselves in trouble, and they are
sending out these letters as a legal ploy to try claim it was somebody else.

I have three US Digital encoders on my Hurco KMB1.

I found the implication and tone of the letter to be vulgar and insulting.
Basically it said over and over again, "You agree to obey the law."
(Paraphrasing)