These are rules about what providers have to do. Also, they are about blocking certain unused numbers (that is, unused for text messages), and it doesn't seem t

These are rules about what providers have to do. Also, they are about blocking certain unused numbers (that is, unused for text messages), and it doesn't seem to be based on the content of the text messages. Somehow the providers need to get lists of these numbers and it's only going to be as good as the providers' information sources. I suppose a government agency could put someone else's number on a list, but that would be rather obvious.