An Airbnb host had to ban crypto mining after guests racked up a $1,500 electric bill

• Airbnb host Ashley Class said she had to ban crypto mining at her North Carolina property.
• She said guests ran up a $1,500 electricity bill after bringing many computer rigs into the home.
• The guests, who made $100,000 during the stay, eventually paid her back, Class said.

Some Airbnb hosts have long lists of house rules , which can range from no pets to instructions on how to change the linens before you leave.

One North Carolina host has had to add another: no cryptocurrency mining.

On July 30, Airbnb host Ashley Class said in a video posted to TikTok that she had banned crypto mining in her short-term rentals after a bizarre guest experience.

At first, guests who checked into one of Class's rentals in Charlotte, North Carolina, presented no red flags. They were "five stars all the way," Class said, with no issues or hiccups during their stay.

That is, until the electric bill came. During their three-week stay, the guests ran up $1,500 in utility charges.

Class went back and looked at footage from her outdoor camera, and saw that the guests had hauled in at least 10 computer rigs , which she later figured out were for crypto mining.

Cryptocurrency mining requires individuals to solve complex mathematical equations to receive shares of digital cash. Many crypto "miners" employ supercomputers — which use tons of electricity — to solve these problems as quickly as possible. Environmental and financial concerns over the rise of crypto mining have led some provinces in China to outlaw the practice .

"It was cheaper for them to rent a house than to pay for that electricity," Class said in her video. When reached by Business Insider by phone, Class declined to share further details of the incident.

Class also said in the video that she messaged the guests and explained she would be charging them for the exorbitant electric bill. According to comments she posted on the TikTok video, the guests fought her until she got Airbnb involved and shared documentation of the incident.

The guest apparently had the funds to repay her, as Class shared in the comments that they made $100,000 during their three-week stay .

Some commenters on TikTok, who appeared to be Airbnb hosts, mentioned they have also explicitly banned crypto in their listings.

"I also have in my rules no crypto mining. It's ridiculous we have to do this," TikTok user @Momma2Macy wrote.

At least one other host said they were running to update their own rules.

"I've never heard of this, but thanks for the heads up! Heading to update my listing," user @blanket1_1 commented.