Last week, Facebook announced that it would begin “temporarily” banning the sale of medical face masks on its online marketplace “over the next few days” in light of the public’s growing fears over the novel coronavirus. But as of Monday morning, listings for face masks, some going for exorbitant prices, still littered the platform.

Some Facebook Marketplace listings were only hours old, while others had been up for days. The Verge was able to find listings located in states across the US with some sellers offering to mail them to buyers for an additional fee. The face masks were being sold for anywhere from 75 cents to $1,000 apiece. “Don’t get caught off guard when someone coughs next to you,” one listing from Kansas City, Missouri, read. “Last ones in the city.”

The face masks were being sold for anywhere from 75 cents to $1,000 apiece

“Supplies are short, prices are up, and we’re against people exploiting this public health emergency,” tweeted Adam Mosseri, the head of Facebook-owned Instagram, last week.

When users search for “coronavirus” on Facebook Marketplace, no listings appear. But they’re still available when searching for queries like “n 95,” “n 95 mask,” “CoVid-19” and “face mask.”

Facebook uses a combination of automated systems and flags from users to remove the listings. “We also have a dedicated channel for local governments to share listings they believe violate local laws,” Facebook said in a blog post. Facebook has also said it will update its policy regarding the ban as it detects new ways people are evading it.

“We’re monitoring COVID19 closely and will make necessary updates to our policies if we see people trying to exploit this public health emergency,” Facebook director of product management Rob Leathern tweeted Friday. “We’ll start rolling out this change in the days ahead.”

Over the past few weeks, people have started buying face masks at an incredible pace to protect themselves from the novel coronavirus outbreak, creating a shortage of protective gear for health care workers, the World Health Organization said last week. The Centers for Disease Control and Prevention (CDC) and other health experts have recommended against healthy people wearing masks as protection, as they’re more useful for health care employees and those who are suffering from preexisting conditions that could make them more susceptible to illness.

Facebook’s temporary ban was announced around the same time that Amazon said that it would not ban face masks and other products, but it was working with state attorneys general to catch sellers on its platform that were engaging in price-gouging.

eBay also banned the sale of medical face masks in the US on its platform last Friday. It’s more difficult to find listings for the products when searching for terms like “coronavirus” or “CoVid-19,” but if users search for “face masks” or “medical face masks,” the products are far easier to locate.

“Like so many companies, we have been closely monitoring the coronavirus issue as it continues to develop,” an eBay spokesperson told The Verge. “eBay is taking significant measures to block or quickly remove items on our marketplace that make false health claims. We are making every effort to ensure that anyone who sells on our platform follows local laws and eBay policies.”

Facebook and other social media platforms, like Twitter and TikTok, have partnered with WHO and other government agencies to provide accurate information for people searching for coronavirus queries on their platforms. For Facebook, if a user searches for a query related to “coronavirus,” the first box that appears is a link to WHO’s website. WHO has also started posting information related to the outbreak on its own accounts, and it created a TikTok page last week to cut back on misinformation.

Updated 3/9/20 at 3:46PM: Included Facebook’s system for removing the listings.