Prank calling was definitely still alive and strong in the 90s. At least they were we me and my friends. And not the "heavy breathing" kind, just silliness. In middle school I spliced a phone cord so my friend and I could prank from the same room. When we got 3-way calling, we would be able to prank with each other from afar AND we could each call another (unsuspecting) party and get them on a you-called-me call together. Good times :)