[ceejayoz]

We went through the same thing a couple years ago with an SMS short code. Had to submit a script (despite it being dynamically driven), set a max number of messages per month (despite it being user-initiated), etc.

The real kicker is we once got a massive nastygram from Verizon threatening us with shutdown - they claimed we were sending porn spam messages via the number. After quite some time auditing our entire stack we got a "our bad, one of our techs had malware on their Android phone" email.