When I worked for an Australian telco (not Vodafone), some developers on another team had used a very conspicuous mobile phone number in their integration tests, which actually connected to a real SMS service somewhere else in the company. No idea why they would do this. It turned out that this number belonged to a real person, who got absolutely buried in test SMS messages, when the integration tests ran as part of a CI/CD pipeline. The owner raised a complaint to the ombudsman, which led to all kinds of trouble for the developers.

In case anyone else here is curious, the ACMA maintains a list of reserved numbers for use in creative works, which you can use for dummy data: https://www.acma.gov.au/phone-numbers-use-tv-shows-films-and...

I worked for an Australian insurance company and we physically DDOSed a poor man's real mailbox with printed policy documents as we used their address during e2e testing and we mistakenly didn't put a testing flag somewhere.

Our CTO had to personally apologise to him

I worked at a grocery retailer, and we had the same exact thing. The CI/CD pipeline was firing out order related SMS messages to a contractor's number during test runs for years.

I wonder how common something like this is.

0412 345 678

That was one number we were told to stop using at Internode. I heard similar stories from Optus and Telstra employees.