San Francisco City Attorney Dennis Herrera sent a cease-and-desist letter to startup MonkeyParking Monday, threatening to take legal action if the company doesn't stop selling apps that let people pawn off their public parking spots.

The Italian-based company started offering the service in January, which allows people to sell their spots if they plan to leave, according to The Verge. Customers are also able to participate in a spot-auction, where possible buyers can outbid each other.

"Technology has given rise to many laudable innovations in how we live and work - and Monkey Parking is not one of them," Herrera said.

According to the letter, MonkeyParking has until July 11 to shut down operations or else they will face a lawsuit, SFGate reported.

MonkeyParking is not the only startup facing legal action for businesses activities that Herrera argues are illegal. ParkModo is currently hiring people to occupy parking spots in the Mission District during the peak evening hours and then selling them to promote the company's smartphone app for $13 an hour.

Sweetch, another startup, lets people sell their parking spots for $4, while buyers have to pay $5, The Verge reported. The company said their service enables customers to save 20 minutes so that they don't have to look for a spot on their own.

"We really don't understand why they want to shut us down. We are trying to solve the huge parking problem," said Hamza Ouazzani, co-founder of Sweetch. "The city should understand that the worst thing to do is to accept the status quo: 20 minutes to find a spot, 30 percent of congestion due to parking, which causes pollution and many other problems."

Herrera, citing police code, said drivers can get a $300 ticket for selling their spot, and, as part of California's Unfair Competition law, the company could receive up to a $2,500 fine for each violation.

MonkeyParking has also received criticism from other software developers, such as Ashley Cummings, co-founder of the San Francisco-based startup Carmanation that matches drivers with owners of private parking spots, SFGate reported.

"Companies should look to help solve urban living issues through technology, instead of taking advantage of public property or city residents," she said.

Paolo Dobrowolny, CEO of MonkeyParking, told The Chronicle last month that his company only works to make things easier for people looking for parking spots and those who need a reason to leave a spot.

"We're just providing information when someone is leaving," he said when the startup was introduced in San Francisco. "That is valuable information for everybody."

MonkeyParking declined to comment on Herrera's letter, saying it was still discussing the issue, The Verge reported.

The app is currently only available for Apple devices. Apple also declined to comment on the issue.