In a 25-page decision, Suffolk Superior Court Judge Frances McIntyre denied a motion the protesters filed that would protect them from eviction from their encampment in Dewey Square, a fate that has befallen similar protests across the country in recent weeks.

“While Occupy Boston protesters may be exercising their expressive rights during the protest, they have no privilege under the First Amendment to seize and hold the land on which they sit,” McIntyre wrote in her decision.

Mayor Thomas Menino told Occupy Boston protesters they must leave their encampment in Dewey Square by midnight Thursday or they will face eviction.“We’re going to ask the occupants of Dewey Square to be out there by midnight [Thursday],” said Menino. “[If they’re not] we’ll take further action.”

Yet -- in an imposing prelude to a possible showdown -- an Occupy Boston emergency text sent out before noon called on anyone who stands with the movement to "please make your way to Dewey Square TONIGHT. We need you!" Occupy Boston called an emergency general assembly at the downtown encampment at 1 this afternoon.