Source: National Archives and Records Administration
These days, anyone with a phone and a working knowledge of "buttons" can call just about anyone in the universe, so it's not hard to see how some political leaders can get duped into taking a fake call when they shouldn't have. However, long before technology and the Information Superhighway took telecommunications from an expensive, complicated, and inferior system to a slightly less expensive, complicated, and inferior system, pranking the high ranking took some work.
John Draper, better known as the aforementioned Captain Crunch, took his phone phreaking to a new level when he called the White House and pranked President Richard M. Nixon, a prank that he kept a secret for almost 20 years. He and his fellow hackers not only figured out the exact numbers and signals to reach supposedly protected lines for the CIA and the White House, but they also obtained the official codename, "Olympus," used to summon the man himself to the phone. So when a man who "sounded remarkably like Nixon" answered, the phone phreakers announced that Los Angeles was suffering from a massive toilet paper shortage and quickly hung up.