At 11:59PM ET tonight, the NSA will shut down its systems that collect bulk phone call data from Americans across the US. The move comes as planned, precisely six months after the USA Freedom Act was signed into law.

The legislation called for the NSA to cease collection of bulk phone records, which includes metadata like phone numbers and the duration of calls. Congress provided six months for the surveillance agency to transition its systems, and now the deadline is up. Phone companies like Verizon and AT&T will now hold onto that data, and the NSA will have to apply for permission from a special court to obtain those records on a case-by-case basis. The law also increases transparency — the government will need to provide annual records revealing how many requests for data it makes.

The end of bulk phone metadata collection by the NSA comes two and a half years after security contractor Edward Snowden revealed the agency's massive surveillance programs. While many, including President Obama, hailed passage of the USA Freedom Act as the first major step towards limiting surveillance powers since the attacks of September 11th, 2001, others noted that the law did not go far enough. The bill passed in the Senate by a 67 to 32 vote, with at least four opponents voting against the legislation specifically because it did not do enough to limit the NSA.

In the aftermath of the attacks in Paris earlier this month, some proponents of the NSA's surveillance programs have sought to give the agency back its power to collect metadata from Americans' phone records. Those supporters include Republican presidential candidates Marco Rubio, Donald Trump, and Chris Christie. No change is likely in the short term, though the NSA has requested to hold on to its existing metadata through the winter to help it ensure that the new program is performing adequately.