Fifteen Princeton students took over an administrative building at the Ivy League school Monday afternoon, according to the Princeton Gaza Solidarity Encampment, while Rutgers University protestors have set up an encampment of at least a dozen tents on Voorhees Mall in New Brunswick. The escalating protests come five days after Princeton arrested two students Thursday for starting to put up tents. Protestors there have continued their presence on McCosh Courtyard, with teach-ins and visiting poets, as they called on the university to divest its investments from firms profiting from the Israel-…