In 1972, John T. Draper discovered he could make free long-distance phone calls using a whistle from a Cap'n Crunch cereal box. The whistle emitted a 2,600-hertz tone that got him into the internal authorization system at the phone company.

With another noisy device known as a blue box, Draper -- soon to be known as "Cap'n Crunch" -- made it possible for many to reach out and touch someone without having to pay for the privilege.

And so was born the modern technology hack. It certainly wasn't the first effort to rig something up to avoid conventional protocols, but it definitely helped trigger a decades-long, sometimes-underground movement to maneuver through security, avoid paying for things, and even cause some malicious damage here and there.

The recent spate of security breaches and e-mail invasions including Monday's news trilogy -- the World Economic Forum hack, the JavaScript email wiretapping scare, and the hole discovered in the protocol that is supposed to secure data transmitted wirelessly -- recalls some of the most infamous exploits of the past.

Here, then, is one observer's list of The Greatest Hacks of All Time.

Captain Zap: Ian Murphy, known to his friends as Captain Zap, was the first cracker to be tried and convicted as a felon. Murphy broke into AT&T's computers in 1981 and changed the internal clocks that metered billing rates. People were getting late-night discount rates when they called at midday.

Of course, the bargain-seekers who waited until midnight to call long distance were hit with high bills.

Murphy, now the chairman of IAM/Secure Data System, was the inspiration for the movie "Sneakers."

The Morris Worm: On Nov. 2, 1988, Robert Tappan Morris released a worm that brought down one-tenth of the Internet –- which back then meant he crippled more than 6,000 computer systems.

Named the Morris Worm, this exploit inspired the founding of a governmental anticyber-terrorism team, CERT (Computer Emergency Response Team), to deal with future Morris worms.

Morris made the mistake of chatting about his worm for months before he actually released it on the Internet, so it didn't take long for the police to track him down.

Morris was one of the first to be tried and convicted under the Computer Fraud and Abuse Act, but he only had to perform community service and pay a fine, since the argument was made that the worm didn't destroy the contents of affected computers.

Morris said it was just a stunt, and added that he truly regretted wreaking $15 million worth of damage. That's what it cost to de-worm the machines his critter had penetrated.

Morris's father, Robert Morris Sr., was at the time a computer security expert with the National Security Agency.

The MOD and LOD Squads: In 1993, the Masters Of Deception (MOD) were the first crackers ever to get busted via wiretaps.

The MOD were mostly Phone Phreaks: folks who had fun with the telephone system. They were famous for figuring out ways to avoid paying for long-distance calls, and could also listen in on private conversations, and create huge party lines that allowed many people to chat to each other at one time.

MOD also hacked its way into many a database, including those belonging to the National Security Agency, AT&T, and the Bank of America. They also accessed credit-record reporting agency TRW's computer system, and were able to gain access to credit reports of the rich and famous.

MOD was also famous for the wars they engaged in with the Legion of Doom (LOD), another cracker group that had the reputation of being the headquarters for the most elite hackers.

Due to internal struggles among the members, the infamous cracker Phiber Optik left LOD and formed MOD. The groups then battled each other for the crown of Cracker King for years, until most of them got busted in 1993.

Many say that MOD members would not have gotten caught if they hadn't been competing against LOD; the war made them less cautious than they should have been.

Kevin Mitnick: Snagged by the FBI on Feb. 15, 1995, Kevin Mitnick was the very first person to be convicted of gaining access to an interstate computer network for criminal purposes. He was also the first cracker to have his face appear on an FBI "Most Wanted" poster.

Mitnick was charged with stealing at least $1 million worth of sensitive project data from computer systems, snagging thousands of credit card numbers from online databases, breaking into the California motor vehicles database, and remotely controlling New York and California's telephone switching hubs on various occasions -- and he also possessed the uncanny ability to convince home phones that they were really pay phones.

He has, however, denied cracking the NORAD (North American Air Defense) Command computer, a crack that was widely credited to him, and inspired the movie War Games.

Mitnick was also a champ at what hackers refer to as social engineering, gathering information simply by asking people for it. Many times the passwords he used to enter computer networks were provided by the systems administrators of those networks, who had been convinced that Mitnick had good reasons for needing the passwords.

The Great Bank Robbery: The year 1995 also marked the great Citibank heist, when Vladimir Levin, a graduate of St. Petersburg Tekhnologichesky University, convinced Citibank's computers to transfer $10 million from its customers' accounts to Levin's. Interpol caught up with him at Heathrow Airport and Citibank got most of the money back.

Viruses of destruction: The writers of the two worst e-mail viruses of the 20th century are not heralded as daring crackers. The writers of the LoveBug, which knocked out scores of computer networks last May, were traced to Manila's AMA Computer College, and the investigation sort of fizzled out from there.

Melissa, which stuck in April 1999 -- clobbering 300 companies and affecting more than 100,000 e-mail users within hours of its release -- handily gained a bit of notoriety for its creator, David Smith.

Script Kiddies: Perhaps you need a snappy name to get fame nowadays. In February 2000, a Canadian kid who went by the name MafiaBoy was arrested for launching a denial-of-service attack that brought down many of the Internet's largest sites.

MafiaBoy managed to cripple Amazon, eBay and Yahoo during the week of Feb. 6 and Feb. 14, 2000.

Despite the claims of his lawyer, Yan Romanowski, that "If (MafiaBoy) had used all his powers, he could have done unimaginable damage," it's widely agreed that MafiaBoy was neither ingenious or creative -- he simply ran a computer script that clogged networks full of garbage data.

MafiaBoy gained illegal access to 75 computers in 52 different networks and planted a DoS tool on them which he then activated and used to attack 11 Internet sites by sending up to 10,700 phony information requests in 10 seconds.

The white hats: And lest we forget, for every cracker who rummages around in systems for personal gain or fun, there's also a hacker who rummages in systems and comes back with something cool to share with the world.

Famous white-hat hackers include Richard Stallman, who founded the Free Software Foundation and promoted the idea that software should come complete with its source code; Steve Wozniak, who decided to build a computer because he couldn't afford one, and came up with the first Apple personal computer; and Linus Torvalds, who cobbled together the Linux kernel as a hobby.