Mr Flow, Please try a TMobile number on ZipWhip. You will see it fails. You will now claim that I am lying and that NetNumber has fixed this. So there is nothing I can do to help you.

I have known about this attack since 2012, but I did not publicly talk about how insecure SMS is for promoting an anti-fraud product.

Note, this is just the tip of the iceberg. There are other attack vectors that only I know!