> if they can’t definitively prove who sent it, They already can. There's an internal "billing" code for every call so carrier knows who to bill for having c

> if they can’t definitively prove who sent it, They already can. There's an internal "billing" code for every call so carrier knows who to bill for having carried that call. They don't want to "prove who sent it" because all those billing transactions for carrying those calls add up to significant profit, and they don't want to kill that profit if they don't have to.