The Drug Enforcement Administration takes billions of dollars in cash from people who are never charged with criminal activity, according to a report issued Wednesday by the Justice Department’s Inspector General.

Since 2007, the report found, the DEA has seized more than $4 billion in cash from people suspected of involvement with the drug trade. But 81 percent of those seizures, totaling $3.2 billion, were conducted administratively, meaning no civil or criminal charges were brought against the owners of the cash and no judicial review of the seizures ever occurred.

That total does not include the dollar value of other seized assets, like cars, homes, electronics and clothing.

These seizures are all legal under the controversial practice of civil asset forfeiture, which allows authorities to take cash, contraband and property from people suspected of crime. But the practice does not require authorities to obtain a criminal conviction, and it allows departments to keep seized cash and property for themselves unless individuals successfully challenge the forfeiture in court. Critics across the political spectrum say this creates a perverse profit motive, incentivizing police to seize goods not for the purpose of fighting crime, but for padding department budgets.

Law enforcement groups say the practice is a valuable tool for fighting criminal organizations, allowing them to seize drug profits and other ill-gotten goods. But the Inspector General’s report “raises serious concerns that maybe real purpose here is not to fight crime, but to seize and forfeit property,” said Darpana Sheth, senior attorney of the Institute for Justice, a civil liberties law form that has fought for forfeiture reform.

The Inspector General found that the Department of Justice “does not collect or evaluate the data necessary to know whether its seizures and forfeitures are effective, or the extent to which seizures present potential risks to civil liberties.”

In the absence of this information, the report examined 100 DEA cash seizures that occurred “without a court-issued warrant and without the presence of narcotics, the latter of which would provide strong evidence of related criminal behavior.”

Fewer than half of those seizures were related to a new or ongoing criminal investigation, or led to an arrest or prosecution, the Inspector General found.

“When seizure and administrative forfeitures do not ultimately advance an investigation or prosecution,” the report concludes, “law enforcement creates the appearance, and risks the reality, that it is more interested in seizing and forfeiting cash than advancing an investigation or prosecution.”

The scope of asset forfeiture is staggering. Since 2007 the Department of Justice’s Asset Forfeiture Fund, which collects proceeds from seized cash and other property, has ballooned to $28 billion. In 2014 alone authorities seized $5 billion in cash and property from people – greater than the value of all documented losses to burglary that year.

In most of the seizures examined by the Inspector General, DEA officers initiated encounters with people based on whether they met certain criteria, like “traveling to or from a known source city for drug trafficking, purchasing a ticket within 24 hours of travel, purchasing a ticket for a long flight with an immediate return, purchasing a one-way ticket, and traveling without checked luggage.”

Some of the encounters were based on tips from confidential sources working in the travel industry, a number of whom have received large sums of money in exchange for their cooperation. In one case, officers targeted an individual for questioning on a tip from a travel industry informant that the individual had paid for a plane ticket with a pre-paid debit card and cash.

Most individuals who have cash or property seized by law enforcement do not dispute the seizure. There’s no right to an attorney in forfeiture proceedings, meaning defendants must foot the bill for a lawyer themselves. In many cases, forfeiture amounts are so small that they’re not worth fighting in court.

Forfeiture cases are also legally complex and difficult for individuals to win. Forfeiture cases are brought against the property, rather than the individual, leading to Kafkaesque case titles like United States v. $8,850 in U.S. Currency and United States of America v. One Men’s Rolex Pearl Master Watch.

While criminal proceedings assume the defendant’s innocence, forfeiture proceedings start from the presumption of guilt. That means that individuals who fight forfeiture must prove their innocence in court.

For these reasons, many defendants don’t bother disputing forfeitures. The Inspector General’s report, however, did find that those who do contest forfeitures often get at least a portion of their cash returned. Only one-fifth of people who had their cash seized by the DEA disputed the seizures in court. But among those who challenged the seizure, nearly 40 percent ended up getting all or some of their cash returned, suggesting that the DEA’s forfeiture net ensnares many individuals not involved in wrongdoing.

In a written response to the Inspector General, the Department of Justice said it had “significant concerns” with the report, noting that global criminal enterprises launder trillions of dollars annually and calling asset forfeiture “a critical tool to fight the current heroin and opioid epidemic that is raging in the United States.”

It also took issue with the Inspector General’s analysis of the 100 DEA cash seizures it examined, saying more of them were connected with criminal activity than the report suggested.

The Inspector General stood by the report and dismissed the Department’s concerns as “assumptions and speculation.” The Drug Enforcement Administration did not respond to a request for comment.

“Nobody in America should lose their property without being convicted of a crime,” said the Institute for Justice’s Sheth. “If our goal is to curb crime, we should simply abolish civil forfeiture” and only forfeit property after a criminal conviction is obtained, she added.