The US government's position has no legs at all in regards to any of this surveillance stuff. They get away with it because of apathy, because of lack of media attention, and because of "might is right".
The congress can simply change the law to make it legal to spy on American seeing the public has no bones.
This is exactly what congress did after 9/11.
That said, Twitter has the means and the money to see this through -- and actually get the W.