Back when you used to call the operator to connect for long distance calls they would ask you which carrier you would like to use. It was a Bell South or Bell Atlantic. In today's world it's do you use AT&T, Verizon, T-Mobile, Cricket, US Cellular etc.. I don't actually know the different carriers as this was before my time but from the sole article left online about it from The Sun Sentinel details how a company KTNT Communications took advantage of companies who couldn't decide and said "I Don't Care" or they said "It Doesn't Matter" and when you said either of those two lines you would have misintentionally been requesting to use one of those services.
Phones had Phreakers and all sorts of interesting hacking back in the day. Today we deal with Sim Swaps and exploits so the hacking has just evolved.
That controversial plan by KTNT Communications who was a Texas company got deferred at the Florida Public Service Commission back in 1987 and even drew the ire of the Florida Attorney General.
For the old but interesting article you can find it here: https://www.sun-sentinel.com/news/fl-xpm-1998-08-27-9808260540-story.html
Other similar stories would be Domain Tasting or Domain Kitting & Phreaking.
