&gt; You have these problems with carriers as well. They&#x27;re technically interoperable but they hit you with prohibitively expensive rates if you try to do anything international.<p>And very poor transparency on those short codes... I once got some extra charges, because of a shortcode (it was actually Yahoo!) I happened use was international. (No way to tell that by the number alone.) It was surprising to hear from the carrier I didn&#x27;t have any way to block international text, too.