Then again, I walked by the Sean Collier memorial most every day when I worked at MIT. I joined the staff shortly the marathon bombing so I never met officer Collier, but it was a daily reminder.
The 9/11 bombers were here on F-1 Student Visas.
Screening of FNs at the border is just fine with me. Having traveled to Israel for work, we are pretty lax at the border here for business and leisure trawlers.