And hundreds of thousands of patriotic americans also have the free speech right to simply say "we don't like what you are saying and we don't intend to give you our cash so that you have a stage to say it on"
It's called "know your customer" chicks. If you want to cater to the London crowd (I'm sure county is huge there), feel free. If you want American country music fans (who are probably 98% in favor of the war), keep your mouth shut.
I also don't recommend getting up and proclaiming that you've had an abortion.
Free Speech, I'd like you to introduce the Dixie Chicks to my friend Free Enterprise...