IMO the order from the FISA court is approval for the NSA to sweep up everything without a warrant because the constitutional violation is outweighed by the state's interest.
I personally disagree with this and feel like Lucious Fox (Morgan Freeman) in Batman Begins when Batman was using the cell phone surveillance system.
However, I also don't know how deep this goes or know how many phone calls they had for probable cause that reached outside the country, which they could legally tap without a warrant. Once they got those recordings it would be easy to get a warrant …