On Sunday evening, as Republican majority leader Mitch McConnell convened a highly unusual weekend session of the Senate, something remarkable happened: a provision of the Patriot Act known as Section 215 passed quietly away in the night.

Section 215 of the Patriot Act was the cloak that allowed the government to spy on almost every innocent, law-abiding person in the United States without a warrant by looking at our call data. Its expiration is a huge milestone for the American people and the Constitution. Our call records are more than just metadata — the numbers dialed and the time and duration of the call. They are intimate portraits of our lives.

Call detail information tells the government how often you talk to a doctor, whether you have ever contacted a priest, or even if you made a call to a suicide hotline. From this, the government can infer information about your religion or even mental health. This is not the kind of information we want our government to have.

We still don’t know how information collected so far will be used in the future. Former high-level National Security Administration staff have admitted how revealing phone records are. Former NSA and CIA Director Michael Hayden said last year, “We kill people based on metadata.” The agency’s former general counsel remarked, “Metadata absolutely tells you everything about somebody’s life.”

Collecting the call records of every law-abiding American isn’t keeping us safe. The government has not been able to prove how the mass phone collection program has prevented a single terrorist attack, despite an estimated cost in the billions of dollars. Despite President Barack Obama’s own disappointing support and use of the NSA’s massive surveillance program, a review conducted by a group he himself appointed concluded that the NSA’s massive surveillance program had never been essential to any terrorist investigation. And just last month, a federal appeals court found that the mass surveillance of telephone records is illegal.

As of June 1 at 12:01, the NSA can no longer collect them. But some in Congress would still like to change that. Over the next few days, the Senate will be considering the USA Freedom Act, a reform bill that claims to strike a real blow against the surveillance state, and rein in the NSA’s ability to collect our phone records. The law, which passed by an overwhelming, bipartisan majority in the House, would prohibit the NSA from storing those records. Instead, it would leave the storage to the phone companies and require the intelligence agency to get a court order to access them.

While this reform is commendable in spirit, it is also not a significant enough reform. For one thing, the court that issues the orders allowing the NSA to obtain phone records — the Foreign Intelligence Surveillance Court, or FISC — almost never denies the agency’s requests. Of the more than 33,900 surveillance applications from 1979 through 2012, the FISC has rejected only 12. And for another, the bill doesn’t address many of the other surveillance authorities that allow the NSA to spy on us. Our country needs a vast overhaul of our intelligence agencies’ surveillance powers, not tinkering around the margins.

We urge all lawmakers — particularly Sens. Angus King and Susan Collins — to push for more comprehensive surveillance reform. They should start by not allowing the Senate to water down attempts to substantively reform the NSA any further. Second, they should use the expiration of Section 215 as a starting point to have a long-overdue discussion about how to protect our national security without compromising our liberty and privacy.

We do not have to choose between security and liberty. We can replace the bulk phone collection program with smarter intelligence-gathering systems that protect our constitutional rights while keeping us safe. And we can work to reform other types of government surveillance, including the mass collection of our electronic communications. June 1 should mark the first step towards ending a period of unjustified government intrusion into American lives. We are at an important crossroads and it’s time for meaningful reform.

Alison Beyea is the executive director of the ACLU of Maine. Matthew Gagnon is chief executive officer of the Maine Heritage Policy Center and a former intelligence analyst for a private security firm in Annapolis, Maryland.