Residents of an illustrious San Francisco private street where homes sell for millions have had the street itself bought from under them.
In an expensive city, the homes on Presidio Terrace are in a league of their own.
A Google Earth image depicts Presidio Terrace in San Francisco.
"Among San Francisco's many prestigious communities, there are few that offer the privilege of privacy amid the magnificence of nature", reads the blurb on one property ad. In other words, the common parts of the street that homeowners are usually responsible for, such as sidewalks and medians, have now been sold off.
'We were looking to get title insurance so it could be marketable, ' Cheng said. He and Ms Lam outbid dozens of others to buy the street without seeing it - and are deciding what to do with their investment.
"We could charge a reasonable rent on it", Cheng said, adding he and his wife could stand to profit from the 120 parking spaces on the street.
For the past two years, the couple has been quiet about its plans for what it's going to do with its street - until recently when they revealed they are considering charging money for residents to park along the street, or to open the street up for outsiders to rent their own parking spots.
Cheng and Lam "would like to exploit a bureaucratic oversight to their advantage", the statement said.
Tina Lam and Michael Cheng have secretly been the proud owners of the sidewalks, roads, manicured islands and other previously public areas of Presidio Terrace for two years now.
Cheng says reaction to the sale has been less than neighbourly. One the residents said he had not heard of until May, nearly two years after the auction.
But Scott Emblidge, the lawyer for the Presidio Homeowners Association, has blamed an administrative mix-up for the missed payments.
"The association was shocked". "How would you like it if somebody bought your backyard in a tax sale?"
"It is hard to understand why anyone would buy this property for any amount".
But the association did not know the back taxes threatened ownership of the street, the suit against Lam said.
It is not clear why no one in the association noticed the lapse in tax collections.
Decades of unpaid taxes by the homeowner's association, which run a paltry $14-a-year, caused the city to put the street up for sale to recoup their $994.
Since the bills were never received, no-one paid them.
He argued the sale was unlawful, and requested a hearing to rescind the sale. However, Amanda Fried, a spokeswoman for Treasurer-Tax Collector Jose Cisneros' office, said the move was completely legal and now nothing can be done about the purchase.
It appears the residents of Presidio Terrace will need to learn how to keep their mailing addresses up-to-date and pay their taxes on time.
Ms Lam, meanwhile, denied any intent to make exploit the residents, and said the pair are in no hurry to sell up.
"I'm a first-generation immigrant, and the first time I came to San Francisco I fell in love with the city", said Lam, who was born in Hong Kong, came to the United States for college, and now works as an engineer in Silicon Valley.