“All the workers sign them,” he conceded. Conversation over.

I introduced myself to a guy sitting behind a table across the street from the house — he seemed to be a foreman or at least someone handing out the badges the workers all wore — he said the place was “just a house” and handed me a card with an email address for Facebook public relations, but no name.

A neighbor walking by was more expressive. “It’s outrageous,” she said of Mr. Zuckerberg’s yearning for privacy, as well as all the activity on the block. “Look at this privacy. It’s been like this for two years. Where’s the concern for the neighbors?” Her first name was Sharon, and she said she was a retired, early-generation techie but declined to give her last name, saying she feared “retribution.”

An email sent to the contact at Facebook provided by the work site overseer was not returned. A Facebook spokeswoman said the company did not comment on Mr. Zuckerberg’s personal affairs.

The lawsuit against Mr. Zuckerberg involves a different residence, 35 miles south in Palo Alto. In it, a part-time developer named Mircea Voskerician claims that he had a contract to buy a $4.8 million house adjoining Mr. Zuckerberg’s residence, and offered to sell a piece of the property to Mr. Zuckerberg. He says that in a meeting at Facebook headquarters in Menlo Park, he discussed a deal to sell his interest in the entire property to Mr. Zuckerberg. In exchange, he says, Mr. Zuckerberg would make introductions between him and powerful people in Silicon Valley, potential future business partners and clients.

Mr. Voskerician passed up a better offer on the house, the suit contends, but Mr. Zuckerberg did not follow through on the pledge to make introductions.

Documents filed on Wednesday in Santa Clara County Superior Court by Mr. Voskerician’s lawyer, David Draper, raised the stakes in the case by asking for access to Mr. Zuckerberg’s net worth. The request is aimed at establishing how much Mr. Zuckerberg could pay in punitive damages, should a jury find he committed fraud. But of course, it also would also threaten to expose Mr. Zuckerberg’s personal financial information beyond what is already known about his Facebook holdings.

Mr. Draper said he deposed Mr. Zuckerberg on Wednesday in a law office in San Jose, but declined to comment further. Patrick Gunn, a lawyer for Mr. Zuckerberg, said that the lawsuit had no merit and that his client intended to fight it “vigorously.”