Is no one going to mention that the named source is ex-Israeli Unit 8200, whose alumni themselves have a long record of espionage in the US telecom sector?
Questions to ask when making up your own mind on this issue: AMDOCS billing customer list includes how many major US telcos? How much customer data is required to generate a bill? How much billing is executed in real or near-real time? How much is hosted off-site on non telco infrastructure? How many non-billing services? (Someone elsewhere here already mentioned 100% of voicemail is now outsourced to AMDOCS at one telco). Incidentally, the source for this article is also conveniently based in Maryland.