With technology radically changing how their customers find restaurants and place orders, San Francisco restaurant owners at a hearing Wednesday said they opposed the increasingly common practice of food delivery apps listing their businesses without permission.

The special hearing called by the Small Business Commission on Wednesday sought to understand the impact of delivery apps and ghost kitchens on traditional brick-and-mortar restaurants in San Francisco. Ghost kitchens, also known as cloud, virtual or commissary kitchens, are venues where food is prepared for delivery or takeout but no sit-down meals are served.

Many restaurateurs who spoke at the hearing said they supported virtual kitchens, and some said they used such facilities to expand their business amid rising customer demand for meal deliveries. But they criticized Postmates, Grubhub and DoorDash for listing restaurants without their knowledge on their apps and websites.

“It’s thuggish behavior,” said Pim Techamuanvivit, who owns the Michelin-starred Thai restaurant Kin Khao in Union Square. Techamuanvivit complained on Twitter last month after she found out that Grubhub had listed her restaurant — which doesn’t offer takeout or delivery of any kind — without her knowledge or permission.

“They basically say, ‘Well, you really want to do this with us because if you don’t, your customers won’t be happy with you,’” she said. Grubhub at the time said the listing was a mistake.

The Small Business Commission, an advisory group, cannot create or pass legislation but does offer guidance to the Board of Supervisors and the mayor on issues affecting the business community.

Vikrum Aiyer, Postmates’ vice president of global public policy, was the only representative of a delivery company who spoke at the hearing. He said these issues should be sorted out between businesses, not through legislation.

Postmates and DoorDash are based in San Francisco, while Grubhub is based in Chicago. Uber of San Francisco also has a food-delivery business, Uber Eats.

Food-delivery apps are increasingly listing restaurants whether or not they have a deal with them to gain market share in a highly competitive market. Aiyer said restaurants should be given tools to remove themselves from the sites. But restaurateurs at the hearing responded that they shouldn’t have to remove themselves from a service they never signed up for.

Anjan Mitra, co-owner of Dosa, a Fillmore Street restaurant known for South Indian food, emphasized the need to look at the larger issues affecting physical restaurants: city policies, high costs and scarcity of labor.

“You can’t solve the symptom of an issue,” he said. “Regulating virtual kitchens is not going to help brick-and-mortar restaurants.”

Mitra, who works with a venture-backed commissary kitchen called Virtual Kitchen Co., said delivery was “a force that’s coming.”

San Francisco counts six licensed commissary kitchens, large complexes housing multiple tenants. These are places where food is prepared for delivery. A Department of Public Health representative at the hearing said these six venues have obtained the necessary permits to operate and handle food, like physical restaurants must do, and are subject to inspections like regular restaurants.

But zoning rules may give virtual kitchens an advantage. Most have obtained permits as catering businesses, which can bypass some requirements restaurants face.

Such operations are not subject to zoning rules that limit chain stores in the city. A fast food chain could set up shop in a virtual kitchen and do delivery in San Francisco without facing the reviews a physical outlet would undergo.

Commissioner William Ortiz-Cartagena said he knew of a chain restaurant already doing this but did not name it.

“The legislation that has gone on in San Francisco has killed our restaurants and now we literally have ghosts roaming around,” Ortiz-Cartagena said.

“We’re here to protect small business,” said Sharky Laguana, president of the commission. “At a minimum, a small business should have agency over who they do business with. The right moment to step in and create regulation is when an industry is unable to regulate itself.”

The commission plans to meet March 9 to further discuss the issues raised at the hearing.

Shwanika Narayan is a San Francisco Chronicle staff writer. Email: shwanika.narayan@sfchronicle.com Twitter: @shwanika