Suppose cell phones had existed when Malcolm X was alive. If he carried one with him then his location could be tracked. Anyone he met who also carried a cell phone could be identified. This would not even involve listening to any actual calls which might be illegal. Your cell phone is being tracked by computers all of the time, unless it is turned off. What are the laws for cell phone tracking?
Doing the calculations to determine his position would involve trigonometry and algebra but that would be coded into the computers. So whoever wrote the programs would have to know the math. But once coded The FBI would not need to know the math.
So the "brainy" people are tools of the "smart" people.