The detention of a Chinese national accused of posing as a Filipino for more than two decades has sharpened concerns in the Philippines that identity fraud could be used to gain access to sectors vital to national security.Immigration authorities arrested Lawrence Ke Sy, president, largest incorporator and majority shareholder of Maxipro Development Corp., on June 27, although the arrest was only disclosed to the public on Monday.Maxipro is a contractor involved in projects for the National...