Norman Siegel, a prominent civil-rights lawyer who visited the protesters on Wednesday night, said a decision by a federal court in Manhattan arising from a lawsuit in 2000 allowed the protesters to sleep on sidewalks as a form of political expression so long as they did not block doorways and took up no more than half the sidewalk.

The protesters first cited that ruling last week while sleeping outside bank branches near Union Square, but said this week that they wanted so-called sleep-outs to occur nightly around the New York Stock Exchange.

An organizer, Austin Guest, said protesters had scheduled such events for Friday night at four other spots, each related to the Occupy Wall Street message that the financial system benefits the rich and corporations at the expense of ordinary citizens.