When an appeals court ruled last week that the National Security Agency's collection of telephone metadata was not authorized under section 215 of the Patriot Act, it blew an enormous hole in the government's legal justification for the controversial surveillance architecture put in place after September 11, 2001.
Now, it's up to Congress to decide whether it will reauthorize section 215 to permit the government's collection of telephone data.
CBS News Senior National Security Analyst Juan Zarate says that the question is whether Congress will "refashion section 215 to actually authorize the NSA program, and of course, that brings out the fundamental debate as to whether or not Congress is going to authorize this program at all, or if it's going to restrict it."
If Congress fails to pass legislation preserving the NSA's data collection before June 1, and the appeals court ruling isn't overturned by the Supreme Court, Zarate warned, the consequences could be grave. "You have potentially the NSA having to abandon this program, because it does not have a legal basis, at least under the Patriot Act, to collect [the data]," he explained.
Given Congress's capacity for handling big disputes and meeting deadlines, though, whether lawmakers will rise to the occasion is anyone's guess.
"It's going to be a real challenge and test of Congress to see if they can balance what is a really serious question for our national security," Zarate said.
Opponents of the data collection program have argued that it's an unconstitutional invasion of privacy - that the government doesn't have the right to collect telephone data about Americans without first obtaining a warrant. Proponents, though, have said the program is a valuable tool to protect national security, and they've emphasized the limits on the data the government collects - the NSA does not receive the content of phone calls, only the phone numbers involved and the length of each call. To follow up on any suspicious activity and actually probe the content of the phone calls, the government must obtain a warrant from the Foreign Intelligence Surveillance Court.
There were already several NSA reform ideas percolating before the court ruling came down last week. Zarate noted that under one measure, passed by the House of Representatives on Wednesday, the telephone companies themselves would hold the data, rather than the government. The government would then need a warrant to access specific portions of the telephone metadata it currently collects in bulk.
But one problem with that approach, Zarate said, is that there's no guarantee that housing the data with the phone companies would do anything to protect privacy. "That can be hacked into, it can be accessed by litigants, so it actually exacerbates the problems you have with privacy and civil liberties," he said.
Another problem, he said, is that by disaggregating the data and forcing the government to petition a court for each individual piece of data collected, the system becomes far more inefficient - and potentially far less effective at detecting threats.
"That slows the process, that builds a requirement that there's actually something very specific about that piece of metadata before you inquire," he explained. "If you disentangle the aggregation of the data, it begins to create some technical problems and some inefficiencies."
Still, he added, "Some would argue, look, it's worth the inefficiencies, we want to protect at least the perception of privacy and civil liberties."