You hit the nail on the head !!
I too have found an OSP mystery charge on my ATT bill, and I now have to go back and check if I've innocently paid earlier bogus charges.
But are ATT, Verizon and other such companies parties to this fraud?
I never authorized ATT to accept these charges, so my guess is that they look the other way and process them because they get a portion in the way of a kick-back.
Even a single charge, multiplied by millions of subscribers is a monumental monthly take, equivalent to white collar crime with an assault weapon !!