Connecting the Dots
Can the tools of graph theory and social-network studies unravel the next big plot?
The Plumber's Helper
It's in the nature of secret intelligence programs that most of us
will never know for sure what the programs do, how well they work or
even whether they exist. Nevertheless, in a democracy citizens can't
entirely cede responsibility for what their government may be doing
behind the black curtain. To have an informed opinion, we need to
puzzle out the facts as best we can. Besides, it's an
My own opinion, so far, remains ill-formed. Tracking terrorists
through call graphs looks like a hard problem. But just because
I'm stumped certainly doesn't mean it can't be done!
Whether or not call graphs lead to hidden terrorist cells, they may
be just the ticket for other tasks. Here's one idea. The Bush
administration has expressed displeasure with the public disclosure
of all the new surveillance programs, and would like to know who
leaked the news. The call graph might be an ideal device for
answering that question. One need merely list, on the one hand, all
those who had access to the information, and on the other hand the
journalists who ultimately reported the story. Search in the graph
for direct or indirect connections between those two sets of
vertices. The irony is that whoever released the information
probably understood quite clearly this potential for exposure.
© Brian Hayes