The US intelligence agencies are among the most powerful forces to ever exist, capable of ingesting and retaining entire nations’ worth of data, or raining down missiles on targets thousands of miles away. As of January 20th, all that power will be directly answerable to Donald Trump.

It’s still early, but a picture is starting to emerge of how the president-elect could use those powers — and it’s not a pretty sight. Since the September 11th attacks, the US government gives the president almost unlimited discretion in matters of national security, with few limitations or mechanisms for oversight. That includes NSA surveillance, as well as the expanding powers of the drone program. And from what Trump has said on the campaign trail, his targets for using those powers may cut against some of America’s most important civil rights.

The crown jewel of that system is the NSA, and there’s reason to think it will grow even more secretive and voracious in the Trump administration. Trump’s current transition team includes two of the NSA’s foremost defenders — Rep. Devin Nunes (R-CA) and former congressman Mike Rogers — a move that suggests the agency will be moving toward more invasive collection and less transparency than ever before.

“No warrant or court approval is required”

To a large degree, those changes can be carried out completely in secret, without authorization from Congress or even the FISA court. The majority of the NSA’s operations are authorized under a little-known presidential mandate called Executive Order 12333, which authorizes collection of data inside and outside US borders for national security purposes. Because it’s an executive order rather than a law, it can’t be challenged in court or overturned by Congress, and it places almost no limits on what the NSA can collect.

“Executive Order 12333 contains nothing to prevent the NSA from collecting and storing all such communications — content as well as metadata — provided that such collection occurs outside the United States in the course of a lawful foreign intelligence investigation,” a former State Department section chief wrote in 2014, explaining the importance of the order. “No warrant or court approval is required, and such collection never need be reported to Congress. None of the reforms that Obama announced earlier this year will affect such collection.”

We don’t know how thoroughly the NSA has exploited that authorization in the past, but, EO 12333 will give Trump a clear path to push the authorization even further. More importantly, because of the secrecy shrouding even the most routine NSA policies, we might not have any idea when a change in policy is made. “It’s very much within the authority of the president to make changes there,” says the Brennan Center’s Elizabeth Goitein, who co-directs the center’s Liberty and National Security Program. “There could be a significant expansion of those activities without the public having any knowledge of it.”

“There could be a significant expansion of those activities without the public having any knowledge of it.”

Secrecy is crucial because it enables more invasive and disruptive forms of surveillance, according to University of Washington Professor Ryan Calo, who has written extensively on the topic. As long as surveillance programs are secret, it’s nearly impossible to hold them in check — and without a steady stream of whistleblowers, any new programs are likely to stay secret. As Calo told The Verge, “It’s very difficult for the public to resist surveillance that they don’t know about.”

That blank check is particularly troubling given the views Trump expressed on the campaign trail. At a rally last November, he stated explicitly, “I want surveillance of certain mosques,” a view he maintained in later speeches. Trump also stated he would take similar measures toward the Black Lives Matter movement, calling the group a “threat” and saying “At a minimum, we’re going to have to be watching.”

“I want surveillance of certain mosques”

There’s also concern about Trump’s penchant for personal feuds, seen on the campaign trail against the Khan family and Alicia Machado. “This is a person who does not suffer criticism particularly well, and holds grudges against political enemies,” Goitein says. “One of the things we saw when we had unfettered intelligence agencies in the past, like J. Edgar Hoover’s FBI, was surveillance and harassment of political enemies. I certainly think that’s something we need to be on the lookout for.”

Beyond surveillance, the Trump administration will also inherit unprecedented powers to unilaterally kill suspected terrorists. Since the drone programs began, US drone strikes have killed as many as 5,000 people, including at least one US citizen, and none of those powers have been meaningfully weakened under the Obama administration. There’s an involved chain of command when those strikes are made through the Joint Special Operations Command, but the CIA operates a separate drone strike program that’s far more malleable. The ACLU had urged Obama to curtail those powers before leaving office, but he declined to do so. The result, two ACLU lawyers wrote earlier this year, is that “whoever prevails in November will inherit a sweeping power to use lethal force against suspected terrorists and militants, including Americans.” Combined with Trump’s outspoken enthusiasm for torture and targeting terrorists’ families, the result could go beyond many of the most barbaric elements of the Bush-era War on Terror.

“We have taken some pretty dramatic steps to expand executive power”

Trump’s first hurdle in carrying out that agenda may be simple workforce issues. A report last week in The Washington Post found significant opposition to Trump in the intelligence community, stoked by the president-elect’s refusal to accept the Director of National Intelligence’s conclusion that the Russian government was responsible for the theft and leaking of emails from the DNC. Because of that bad blood, insiders predict a significant backlash if the incoming president scrapped the previous administration’s rules on drone strikes or attempted to restart the CIA’s torture program. The Daily Beast found similar unrest at the Pentagon, as old guard officials anticipated being replaced by a younger generation. Still, with the power to promote and dismiss leaders at will, it’s difficult to say whether staff unrest will end up being more than a speed bump for Trump’s ambitions.

There’s also Congress, still controlled by Republicans but arguably containing as many surveillance opponents as ever. “I think the relationship between the Trump administration and the Republicans will be interesting,” says Calo. “A congressman like Justin Amash is going to be just as vehement about the need for citizen privacy as he was under Obama.” Still, it seems unlikely that those efforts will be more effective under Trump than they were under Obama.

In some ways, the problem is larger than even Trump himself. These presidential powers are still new, and Obama is the only president to enter office with them already in place. For scholars like Goitein, that sweeping power is the real issue. “Before 9/11, the law required suspicion of criminal or terrorist activity before we could conduct surveillance, and that’s no longer the case,” she says. “We have taken some pretty dramatic steps to expand executive power, and I’d say no matter who had won the election, we’ve reached a point where we really need to rethink whether that’s in our best interests.”

It’s a point that was echoed by none other than Edward Snowden, who responded to Trump’s electoral win in a livestream on Thursday. An occasional critic of Hillary Clinton, Snowden struck a tone of hope and resilience, putting the election in the context of troubling new surveillance laws in Russia and China.

“Something we need to remember is that we are never farther than a single election away from a change in government, a change in policy, a change in the way the powers in our system are used,” he said from an undisclosed location in Russia.

“What we need to start thinking about now is not, How do we defend against a President Donald Trump?” he continued. “How do we defend everyone everywhere?”

Correction: A previous version of this article referred to Prof. Ryan Calo’s parent institution as the University of Wisconsin. It is the University of Washington.

Watch: It’s up to America’s institutions to check Trump