Beware the eyes of Trump.

Immigration and Customs Enforcement is reportedly trying to join the network of federal departments that can access warrantless surveillance information gathered by the spies at the National Security Agency. U.S. Customs and Border Protection is trying much the same thing.

The prospect of these two law enforcement agencies gaining access to such intelligence should send chills down the spines of illegal immigrants — and all Americans.

The NSA was originally handed extra-constitutional spying tools to keep an eye on foreign threats — not assist in routine law enforcement by domestic agencies. But it hasn't worked out that way. For many years, this spy agency has been sharing all kinds of information with law enforcement. It claimed that it was taking care to scrub out sensitive and private details about innocent Americans. However, since 9/11, it has come under pressure to abandon even such minimal restraint and share unfiltered information so that law enforcement doesn't miss crucial clues about burgeoning threats.

Instead of resisting these demands, President Barack Obama, a constitutional law professor who should have known better, threw open the NSA's entire treasure trove of secret information to 16 agencies, including the Department of Homeland Security, the FBI, and the Drug Enforcement Administration.

However, he pointedly left out immigration enforcement agencies like ICE and CBP. But in Donald Trump, the duo has a simpatico president, which is why they have renewed their quest to join the spy community.

If President Trump obliges, what information will these agencies obtain?

The NSA employs tools of mass surveillance that, in theory, it is supposed to use only on foreigners outside the country. But the reality is very different, if for no other reason than we live in a digital world where information flows seamlessly across borders.

Americans who correspond with any foreigner that the NSA is watching instantly become fair game. Their information is secured on servers abroad that the agency routinely taps. Emails, text messages, and vast amounts of internet data are vacuumed in. The NSA has targeted entire Yahoo and Google data centers abroad, all of which contain communication by Americans. It also intercepts and archives every cell phone call to and from the Bahamas and other Caribbean countries. It gathers millions of text messages in global information sweeps. This is not just metadata, but actual content. The NSA listens in on and records phone conversations, reads and downloads text messages, hacks into emails and copies exchanges. (In one instance, NSA agents were amusing themselves by listening to recorded conversations of Americans engaged in phone sex.)

Nor does this information just sit there in untouched archives. The NSA has powerful search engines to rifle through its databases to dig up information about any American for any reason without ever obtaining a court order, basically eviscerating the Fourth Amendment's protections against illegal searches and seizures. Some agents have even used these tools to spy on their exes.

The NSA gets the legal authority for such activity from Section 702 of the recently reauthorized FISA (Foreign Intelligence Surveillance Act) that has nominal congressional oversight but no judicial check —and the notorious Reagan-era Executive Order 12333 that has neither. In other words, the order uses executive authority to give an executive agency unchecked spying powers.

Handing ICE and CBP, which have vast powers to track the physical movements of people in America, unfiltered access to this massive surveillance would be problematic under any circumstances. But it is especially so when these agencies are expanding their own internal spying capacities in the name of interior enforcement.

Last month, ICE signed up with Vigilant Solutions to access license plate databases that the company has created by taking pictures of unsuspecting vehicles on toll roads, parking lots, and other public places. This will give ICE the means to do near real-time tracking of targets suspecting of breaking immigration laws, especially since the Supreme Court has not outlawed remote warrantless GPS surveillance that doesn't require it to plant physical device on vehicles.

Meanwhile, CBP is in the process of creating facial recognition technology that will essentially turn people's faces into their papers. This will mean enhanced tracking of foreigners and citizens any time they go in and out of the country. But border patrol also has near carte blanche to set up interior checkpoints and stop buses and vehicles within 100 miles of the border. This is a huge swathe of land: Two-thirds of Americans live there. So every time anyone — American or not — passes through these checkpoints, their movements will be potentially scanned and recorded.

If ICE and CBP gain access to the NSA's surveillance and combine it with their own spying capacities, they will literally obtain Big Brother-style powers to track and monitor almost anyone on U.S. soil. And they will be able to use this information to detain, arrest, and go after people in other ways. This should be terrifying to all of us.