Those were done in the late 90's by tricking an internet provider into forwarding their toll-free lines to my house so that all of their customers would reach us instead of them.
It lasted 2 or 3 hours and ended with a call from the owner of the ISP calling me and asking WTF was going on. I yelled at him for making my phones ring all day and tying up the phone lines that I use for work. I think I threw in a "your stupid phone calls woke up our sleeping babies!" for good measure and told him we would call the police on him if we received any more phone calls.
There were a lot of calls that I didn't keep, like the few where we helped customers by getting them to type FORMAT C: into their DOS prompts, then laughed at them for erasing all their data.
