All we needed to learn about the Muslim terrorists in North American, we learned in spades on 9/11.
The denial and second guessing is a case of mass hypnosis and denial.
Immigration from terrorist training, hate-mongering regimes like the Palestinian Authority, Syria, Iran, and Egypt should have ceased completely on Sept 12, 2001 and kept that way for as many years as would take to defeat these enemies of democracy and peace.
There is no benefit and extreme harm to the U.S. in taking the poor risk of more pseudostudents, who come here to teach hate on campuses and learn how to make bomb, study Western patterns of daily life so as to catch Americans offguard, and to undermine computers and Internet sites and create high tech terrorist devices.
The governmnet should long ago have banned all visas to Muslims except under very special diplomatic circumstances, and began deporting all non-citizens Muslims.
All the rest,together with their mosques and madrasshes should be under intense scrutiny and continual monitoring.