Meanwhile they supply everything directly to the federal government.
Yes, being ordered and gagged by the US government is coercion. Are you familiar with the article you linked to?
Note: Not taking sides. Only trying to clear up the doubt.
This is false, although it's reasonable to assume that, during the coersion, some specific people or companies do roll over out of self-interest.
FISA court is not a real court in a "rule of law" sense if it is non-public and creates secret law. Both is the case. Also, maybe even more importantly: The FISA court did not even decide on individual surveillance acts under PRISM, but about the program in whole. Both together means that in no way there is a court oversight for this kind of surveillance.