Looks like they’re playing a government version of “Six Degrees of Kevin Bacon.”
Assuming each person in each step knows 25 unique individuals you can reach 6 billion + people in 7 steps. That’s basically the earth’s population give or take.
I have links to hundreds on one alumni email distribution and 300+ on Linkedin. Granted I don’t correspond with them much. But if the alumni email distribution is an indicator - then if 100 unique contacts are reached at each node then the earth’s population is well exceeded in 5 steps.