|
The routing information on transmitted communications provides plenty of information to build screening profiles. You don't necessarily need content analysis of every communication, moreover, you especially want to detect and analyze specific profiles in a timeframe that is operationally useful.
As we saw for 9/11, it took NSA 3 days to detect, analyze and distribute information on 2 phone calls intercepted in Afganistan on 9-10 whose content refered to events happening on a "tomorrow" in a way that may have been statements of the 911 attack date the next day. That only involved telephone calls from Afganistan--I am guessing Afganistan in 2001 had many many fewer telephone calls daily than the US.
Imagine the workload for international communications from or in the US. That information could NEVER be processed to provide information that could prevent an event UNLESS there was a way to prioritize the effort. To do that the NSA undoubtedly uses some sort of profiling, or its euphamism--filtering.
|