What’s the harm in sharing your mobile number?

For some of you, it has (prior to this) been routine to punch in your phone number as an identifier for “club reward” points at the grocery store or other retail location. Yet, for many of us, mobile phone numbers especially follow us from apartment to apartment to home. We don’t change that number often, if at all. It therefore, becomes a good identifier of who we are and tied with other publicly available information, becomes the key to unlock a lot of digital information. The article linked below shows the surprise findings of a tech journalist when he gave his mobile number to a security researcher. (click the picture)