[macinjosh]

I would imagine there are rules/regulations about a SMS provider blocking communications before fraudulent behavior is determined? Not saying it shouldn't/couldn't be done, but probably one of those things with a simple tech fix but a complicating social/business aspect.

[kevincox]

It could be an option in the API call with a default in account settings. I bet most people who are trying to reduce spam accounts by requiring a phone number would actually prefer to exclude these numbers anyways.

[deecewan]

surely not if the customer _explicitly requests_ that the communications are blocked? iirc in Aus it was possible to have your provider block messages to premium rate numbers back in the days when it was popular to buy ringtones.