Steve76,
A for what it's worth.....
In 1985-86, while working for a Federal investigative agency as a Special Agent, I submitted an informal concept proposal to my headquarters for a surviellence operation targeting foreign nationals taking aviation training. The intent of that operation was designed to locate, identify, and target for recruiting those individuals that might have been of use to the US Government in their home countries.
A collateral issue was also the fact that we would have an ability to identify just such questionable acts as led to the 9-11 attack although that was not a consideration at that time and was not ever mentioned.
My Concept Proposal was rejected for being in conflict with the Church Amendment that so severely limited CIA/DOD/FBI operations within the USA.
Ironic isn't it?