SoylentNews

kaszz writes:

Australian telco Optus has been caught passing its customers' mobile phone numbers to third-party websites without the customers knowledge or consent. The practice, known as HTTP header enrichment, aims to streamline the process of direct billing for customers, but they're not happy. The discovery was made by a user on the telco forum Whirlpool, and Optus confirmed it: "Optus adds our customers' mobile number to the information in select circumstances where we have a commercial relationship with owners of particular websites."

I know this is done in other western countries and abused to run you-watched-porn-now-pay-us scams. There's rumors that the practice is used in Russia too.