We live in a world where we need to listen to the law. If someone has hardship with child support etc they should bring it to the judge but the bottom line is dina demalchusa dina and if thats what the law is then we must follow it. A get was never intended to put you above the law or to ignore the law or to bypass the law.
You know what halacha says about someone who goes to ערכאות when they don't follow דין תורה, and someone who reports people to authorities for something which is not against the תורה (AKA a moser).
If you believe that American law takes precedence over Halacha, I'm not sure why you're on a thread discussing gittin. There's nothing in American law about Mamzeirim. Just sprinkle some holy water on them, and they'll be good to go.
If a woman can utilize an unjust privilege provided by American law to make it impossible for a man to move on in life, and you don't blink about that, then why are you so scandalized when the man uses an "unjust privilege" provided by halacha to make it impossible for a woman to move on in life? If you believe in equal rights, than you should be just as bothered by women making men agunos as you are by men making women such.
The Nazis were law abiding soldiers displaying strict obedience to authority. Just ask Mr. Milgram.