it is not the network administrators making those calls or putting them on that list. a job many moons ago:

my phone: ringing off the hook for the past three days. WHY.

CEO: "hey we need better internet access at the new office, I setup a call with Cogent, let me know how it goes"

my phone: answered to find its cogent blowing me up

Cogent: car-salesman methods

me: I quit

Cogent every two months since then: "hey I heard you left your job, any need for business internet access?"