A couple of years ago we had a guy who would call the library and tie up all the phone lines. He would call one line and then another and another eventually tying up all five of our phone lines. We couldn't call out and no one else could call in. We tried every trick in the book from *69 to not hanging up to get him to stop. Eventually we had the number blocked but not before he called the library while a police officer was there filling out a complaint form so I handed the phone to the officer so he could talk directly to the guy and the guy just hung up and called 9-1-1. He kept them tied up for a while which is a criminal offense.
They eventually figured out that the guy was mentally disturbed. He had a caretaker that was supposed to be monitoring him and his behavior (he'd been known to harass other people before) but every time the caretaker would fall asleep he would jump on the phone and start dialing.
