What do you understand by the term phone freaking?

Take note that phreaking used to be popular back in the 90s but with all of the new advancements that are made, what used to be effective in the past are not too useful now. C is an example of phone phreaking. It makes use of a tone that will make the telephone networks allow long distance calls.

This used to be an expensive feature in the past. People would need to pay a lot of money per minute to call to different cities. The costs will be higher when the person needs to place a call to another country. There is no need to do this right now as the internet allows people to call for free no matter what part of the world they are in.