In part because of the attempted bombing in Detroit on Christmas Day, security in Times Square will be heightened this evening. The Times has a rundown of a few reasons it might be better to skip out on the ball drop tonight:
Streets leading in and out of the square will be blocked with metal barriers and police cars. Some subway portals will be shut. Officers with rifles will patrol on rooftops. Others, in plainclothes, will mingle with the crowds to search for pickpockets or would-be terrorists. ... Hundreds of city police officers will have devices affixed to their belts that can detect radiation or the crude makings of a dirty bomb. Machines with similar technology will be on trucks, police boats patrolling the East and Hudson Rivers and on helicopters, [NYPD spokesman Paul Browne] said ... Other devices, deployed by the city’s Environmental Protection Department, will be in place to sniff the air for chemical or biological contaminants, Mr. Browne said. There will be decontamination facilities available, including areas for people to bag their clothes and shower in tents if necessary, he said.
Also, it will be raining.