Homeland Security Secretary Tom Ridge is defending the decision to tighten security in New York and Washington. That's despite the fact that the intelligence behind the latest terror warnings is as much as four years old. A senior Justice Department official says federal investigators are working on the assumption that the plot is continuing. Two counterterrorism officials say information and evidence suggest that terrorists were recently using the information from surveillance activities. The warnings that terrorists might be plotting attacks in New York, Washington and Newark, New Jersey, prompted authorities to elevate the terror alert level for the financial sector in those cities to orange, or high. The intelligence behind the warnings came from sources including a seized laptop and computer discs and from interviews after the mid-July arrest of a young Pakistani computer engineer.