After the U.S. Centers for Disease Control and Prevention announced that fully vaccinated people may refrain from wearing masks in most places, searches and availability for counterfeit COVID-19 vaccination cards being sold online increased, undermining state and federal  attempts to handle the coronavirus pandemic.

Fraudulent vaccine cards have popped up on the websites of major online retailers and the dark web. Amazon.com Inc., Etsy Inc., eBay Inc., Shopify Inc., pro-Trump forums and Craigslist, Inc. are among the most common sites where vendors have already tried selling packs of cards.

The cards are easily replicable. “Sure, there are those CDC COVID-19 vaccination cards people get when they get their vaccine. But they were never designed to prove your vaccination status and they may not be enough,” the Federal Trade Commission said.

COVID-19 vaccination cards are one of the only real ways for someone to track and prove their full immunity, aside from apps like the New York State Excelsior Pass Wallet or CommonPass. These apps were created so people would not have to carry around their physical, white cardstock records.

“Businesses and venues can scan and validate your pass to ensure you meet any COVID-19 vaccination or testing requirements for entry,”  New York’s website said about the Excelsior Pass.

The fraudulent cards are targeting people who need cards, but do not want the vaccine for reasons like hesitancy or fear of it. However, COVID-19 vaccines are free and all the COVID–19 vaccines approved in the U.S. have been effective at preventing the disease, the CDC reported..

One major problem with the fake cards is that it leaves states and businesses confused. Sporting events and universities are requiring people to get vaccinated, so if some people are showing false proof of vaccination, the places will be unsure who is telling the truth, BuzzFeed explained..

Another problem is that people who make fake cards have scanned and taken pictures of cards posted on social media to create new ones. Consequently, the FBI has advised people to not post their cards.

Fake cards may also mean difficulties in travelling.

President and CEO of the Better Business Bureau of Chicago Steve Bernas believes unvaccinated people are at risk of infecting each other.

“If you want to try to get on an airplane and you feel everyone is vaccinated and this person isn’t vaccinated; carrying around a fake card, it’s not good for America or anyone,” he said, according to NBC Chicago.

Some are even stealing cards to give to family members and friends.

As a response to the fraud, attorneys have urged the CEOs of tech companies, such as Twitter, to address the issue in its early stages, according to NPR.

“We do not allow the products in question in our store. We have proactive measures in place to prevent prohibited products from being listed and we continuously monitor our store,” an Amazon spokesperson said in a letter to NPR.

In New York, legislators recently passed a bill that would make it a felony for someone to forge or own a fake immunization record like the card. So far, Senate Bill S4516C has passed senate and assembly status, but it is still awaiting delivery to Gov. Andrew Cuomo.

“New Yorkers deserve to know that when they attend an event or go to a ballgame where proof of vaccination is required that those around them are not putting people at risk by using forged documents,” Assembly member Jeff Dinowitz said, according to Spectrum News.

On a federal level, a fraudulent immunization card could mean either a fine or time in prison. “the unauthorized use of an official government agency’s seal (such as HHS or the Centers for Disease Control and Prevention) is a crime,” The FBI said.

To stay ahead of scammers, the FTC gave advice on their website, suggesting people to limit who they share their information with and check with venues about their requirements.

As of state data from June 14, there are over 4 million people who have been fully vaccinated in New York City in the past seven days.