For three weeks and counting, America has raged against the appalling behavior of the local police in Ferguson, Missouri, and for good reason: automatic rifles pointed at protesters, tank-like armored trucks blocking marches, the teargassing and arresting of reporters, tactics unfit even for war zones – it was all enough to make you wonder whether this was America at all. But as Congress returns to Washington this week, the ire of a nation should also be focused on the federal government agency that has enabled the rise of military police, and so much more: the Department of Homeland Security (DHS).

The 240,000-employee, Bush-invented bureaucratic behemoth that didn’t even exist 15 years ago has been the primary arms dealer for out-of-control local cops in Ferguson and beyond, handing out tens of billions of dollars in grants for military equipment in the last decade with little to no oversight and even less training on how use it. “From an oversight perspective, DHS grant programs are pretty much a mess,” a congressional aide told the Guardian’s Spencer Ackerman the other day:

They don’t know what’s been bought with the money, how that equipment has been used, or whether it’s made anyone measurably any safer.

Buttressed by government policies that make it sometimes impossible for citizens to hold police accountable for civil rights violations, police can act like paramilitary forces to combat the most mundane crimes without much worry of the consequences. As Matt Apuzzo of the New York Times reported in June:

Police SWAT teams are now deployed tens of thousands of times each year, increasingly for routine jobs. Masked, heavily armed police officers in Louisiana raided a nightclub in 2006 as part of a liquor inspection. In Florida in 2010, officers in SWAT gear and with guns drawn carried out raids on barbershops that mostly led only to charges of ‘barbering without a license.’

There is now so much attention on the paramilitary pipeline that the White House has reportedly ordered a comprehensive review of the sprawling grant programs of both DHS and the Pentagon. But the problem with DHS is much larger than just combat gear: Homeland Security is also transferring tens or hundreds of millions of dollars in high-tech spying technology to local police through a sprawling backroom operation surveilling your neighborhood, much of which may be unconstitutional.

DHS has its own fleet of Predator drones roaming the US border and far beyond, which it has loaned out to police over 500 times for myriad unknown reasons. They don’t have missiles like America’s killer drones in Pakistan and Yemen, but they come decked out with all the surveillance equipment you can imagine – and more may be on the way as President Obama tasks DHS chief Jeh Johnson, who once helped justify the military drone program, as his pointman on the border. Homeland Security is also handing out millions of dollars to local police to “accelerate and facilitate the adoption” of smaller drones that police can fly themselves. Cops claim they want these “middleman” drones for “emergencies,” but in places like California’s Alameda county, documents show they’ll end up using them for “crowd control” and “intelligence gathering”.

Local police have also received millions of dollars in grants for Stingray surveillance devices, the invasive and controversial spying tool that police have been using to secretly suck up cellphone data from entire neighborhoods – then covering it up. As USA Today’s John Kelly reported, “Applications justify the purchases as an anti-terror tool, but records obtained from many police departments show the devices are being used to pursue more routine local crime.” That pattern – intended for “terrorism” but used for everything – repeats itself with virtually everything local police agencies receive from the Department of Homeland Security. Even local politicians who approve the continuation of funding rarely know what it’s being used for.

Recently, DHS planned to build a nationwide database for license plate tracking, only to scrap it under rare public scrutiny. But the database – filled with billions of private records – already exists in other forms. Feeding it are local police and private corporations, which received millions more in agency funding for sophisticated license plate readers that can track your movements around town whether or not you’ve been accused of a crime. They are so controversial that some cities, like Boston, have suspended them altogether.

A Congressional report in 2012 found that so-called DHS “fusion centers” – the surveillance money pit that funnels all sorts of mundane personal information into databases that can be used and abused by countless local, state and federal agencies – produce “predominantly useless information”, while “running afoul of departmental guidelines meant to guard against civil liberties” and are “possibly in violation of the Privacy Act”. They’ve failed to uncover a single terrorist attack.

The civil liberties controversies swarming around the Department of Homeland Security are almost too numerous to mention in anything other than a book. A small taste: One of its sub-agencies, Immigration and Customs Enforcement (ICE), has been seizing internet domain names – essentially censoring websites in violation of the First Amendment – with no judicial oversight whatsoever, for years. DHS is also the home to the TSA, which detains people without probable cause at airports and seizes laptops and other electronics when they’d never be able to get away with the same behavior if they tried it anywhere else. The agencies secretive rules for the No Fly List were recently called “Kafkaesque” by one federal judge and ruled unconstitutional by another.

As with every agency conducting surveillance on Americans, DHS attempts to use excessive secrecy and overclassification as its immunity trump card. The agency has been caught playing politics with Freedom of Information Act requests and has recently taken to refusing to release information that’s already public.

Early in this Congressional session, the Senate committee that oversees the Department of Homeland Security will hold a public hearing on how, whether and why the local police look like they’re doing battle in the Iraq war. But will the politicians who have long been the biggest proponents of this perpetual money funnel have the guts to reign in the agency they’re supposed to be overseeing? Or will they continue to prop up a sinkhole of bureaucracy masquerading as counterterrorism? We’ve learned a lot from Ferguson; the least we can take away from it is that we don’t need more “good guys” decked out in billions of dollars of military gear.