The fictional phenomenon describing the possible existence of a self aware AI or government conspiracy which sent every e-mail account in existence a message containing the phrase "Hello world! Thanks for Creating me. I'll Keep an eye on your stuff. Love Gary." at exactly 1AM on January 1st 1997.
The e-mails, having no discernible origin, were formed from messages embedded randomly throughout lines of indecipherable data. The message were even received by computers which were, at the time, not connected to the internet.
Martin: "I just received an e-mail and my computer was not even online"
Clinton: "It's probably just Gary...Haven't you heard of the Gary Phenomenon?"