I can't understand why it is not illegal by way of being unconstitutional since it clearly tramples on the 4th amendment rights of all the other subscribers. A

I can't understand why it is not illegal by way of being unconstitutional since it clearly tramples on the 4th amendment rights of all the other subscribers. Absent clear mechanisms for watching the watchmen to make sure they not only respecting the 4th amendment rights of the other subscribers, but technically incapable of doing so (in order to mitigate rogue actors that want to impress their superiors via fishing expeditions), I can't see why we should have any reason to believe this information will not be abused. The government, especially the NSA and the FBI (by way of parallel construction), have proven to be outright liars. This alone should be enough for a judge to rule against the right of the government to make such broad requests. The government has be proven guilty of lying here. The burden is now on them to show that they are no longer guilty.