Amazon is battling a group of warehouse employees in California federal court.

The White House is cracking down on counterfeit goods sold through online marketplaces including Amazon, eBay and Alibaba, pledging to “attack” the problem on numerous fronts.

President Trump signed a presidential memorandum Wednesday aimed at tackling the issue and revealed that he has tasked the Department of Homeland Security with compiling a report on the problem, which will provide a foundation for any recommended policy changes.

In a call with journalists, Peter Navarro, director of the White House National Trade Council, was reported as saying that third-party online marketplaces have zero liability when it comes to trafficking in these counterfeit goods, which “simply has to stop.”

“This is a warning shot across the bow that it is your job to police these matters, and if you won’t clean it up, the government will,” he added.

The memorandum cited an Organization for Economic Co-operation and Development estimate that the value of trade in counterfeit and pirated goods totals half a trillion dollars annually, with roughly 20 percent of this stemming from the U.S.

What’s more, a recent Government Accountability Office report examined four categories of frequently counterfeited goods and, based on a small sample of these goods purchased through various online third-party marketplaces, found that more than 40 percent were counterfeit.

According to Navarro, it’s too early to say what possible policy changes may be required but the report will investigate the scale of the problem.

In February, Amazon, which prohibits the sale of counterfeits on its site, launched Project Zero, giving brands the power to remove suspected fakes from the web site without contacting Amazon first.

The global market for fakes, which includes the sale of products both online and off-line, was worth $1.2 trillion by the end of 2017, according to the Global Brand Counterfeiting Report. The firm expects that number to jump to $1.82 trillion by 2020.