The US government has been fighting hard to stop a proper adversarial determination on whether it is legal; it is hard to challenge the legality of a secret sys

The US government has been fighting hard to stop a proper adversarial determination on whether it is legal; it is hard to challenge the legality of a secret system without even having all the facts about the system, and an ex parte hearing (i.e. where the only party putting forward arguments is the US government, to a secret court) isn't likely to fully explore the legality. As I understand it (IANAL, I am not an American), the US government is only supposed to spy on people with a warrant, but in this case they got essentially a 'blank cheque' warrant that let them spy on everyone. Such a broad warrant is not due process, because the court is not able to consider the specifics of each case data might be used for before data is collected.