Last week, the 2nd U.S. Circuit Court of Appeals issued its decision in the case of ACLU v. Clapper on appeal from the U.S. District Court for the Southern District of New York. This was the case brought by the ACLU after the public disclosure by Edward Snowden that the National Security Agency had been engaged in the collection and archiving of “bulk” telephone metadata (for instance, the time when telephone calls are made and the numbers of the senders and recipients of such calls) in the United States for several years.

The NSA argued that this type of information collection and archiving was authorized by Section 215 of the Patriot Act, the statute passed by Congress just days after the 9/11 attacks, and approved by the special U.S. Foreign Intelligence Surveillance Courts set up to expedite U.S. intelligence agencies’ requests for warrants for surveillance activities. The ACLU lost their lawsuit in the District Court and appealed to the 2nd Circuit, which, on Thursday, held that the Patriot Act does not authorize the type of bulk data collection the NSA has been doing and left it to Congress to pass a new version of the Patriot Act if it wants the NSA to engage in such intelligence collecting.

The timing of this decision was not without significance. The current version of Section 215 of the Patriot Act expires on June 1 and, therefore, Congress must renew the Act, enact a revised act, or simply let Section 215 of the Act die on June 1. There seems little doubt that the 2nd Circuit decision was intended to tell Congress that simply renewing the Act without a change to Section 215 would mean that the NSA would have to stop its bulk metadata collection program.

Reactions to the 2nd Circuit’s decision have been predictable. Edward Snowden, of course, has made it clear that the decision, in his mind, vindicates his actions. Proponents of the NSA collection program now know that if they want the program to continue Congress must enact a new version of Section 215 of the Act that explicitly authorizes the NSA collection program. This will undoubtedly make the debates on the Patriot Act more heated and the legislative action more complex. Whether Congress can manage to enact such a revised statute in the next few weeks will be extremely interesting.

The debate over the NSA collection program and the need for a new, revised Patriot Act Section 215 is likely to be affected not only by the 2nd Circuit’s opinion in the Clapper case but also by warnings issued last week by FBI Director Jim Comey and Secretary for Homeland Security Jeh Johnson about an increased threat of “homegrown terrorism” inspired by ISIS propaganda. In addition, Admiral William Gortney, the head of the U.S. Northern Command, ordered increased security at all domestic military bases in light of Internet-based ISIS threats to military personnel.

Once, again, Congress will have to decide upon the need to balance American security at home and abroad with the need to protect American citizens’ privacy rights. At this point it is extremely difficult to predict how Congress will decide this issue, but whatever Congress ultimately does will have major impacts both on the safety of American citizens and their civil rights.