This just outlines another spot where having a sufficiently open operating system on your mobile does make a lot of sense. In android, I could implement my own

This just outlines another spot where having a sufficiently open operating system on your mobile does make a lot of sense. In android, I could implement my own SMS application (maybe even just base it on the existing stock one if that's open source - I don't know). This clone would only use the existing notification framework if the sender is in my address book. Then I would just disable the built-in SMS application. Of course this isn't as good as blocking the SMS on the provider level, but on the other hand it provides more granularity than a wholesale SMS block would provide.