I would imagine that most exploits like this, at least if black-mailing the telco is the objective, would be launched through an SMS gateway. There are a limite

I would imagine that most exploits like this, at least if black-mailing the telco is the objective, would be launched through an SMS gateway. There are a limited number of those onto any carrier network, and I suspect that any telco would rather shut those down temporarily than surrender to blackmail. Maintaining the integrity of their relatively closed network and the phones on their network is a lot more important to them than maintaining Twitter's and Twilio's access to said network.