I have no clue why there hasn&#x27;t been much talk about this. Or is it that the people who know are busy monetizing this information?<p>I see that this has been in practice since the last few years. <a href="http:&#x2F;&#x2F;stackoverflow.com&#x2F;questions&#x2F;8428422&#x2F;detect-an-msisdn-mobile-number-with-the-browser" rel="nofollow">http:&#x2F;&#x2F;stackoverflow.com&#x2F;questions&#x2F;8428422&#x2F;detect-an-msisdn-...</a>