A cuckoo egg is an MP3 file that typically contains 30 seconds of the original song with the remainder of the song overwritten with cuckoo clock noises, white noise, and/or voice messages such as, "Congratulations, you must've goofed up somewhere." Ideally, a cuckoo egg should have the same playing length as the music it pretends to be. The purpose of cuckoo eggs is to deter the downloading and sharing of MP3 files using Napster and similar approaches.
Typically, a Napster user downloads an MP3 file and sometimes share it with others before listening to it. Recognizing this, a cuckoo egg creator creates the cuckoo egg to look exactly like a real MP3 file. The user then unknowingly shares the cuckoo egg with other unsuspecting users spreading the cuckoo egg like a virus. Unlike a virus, cuckoo eggs do not damage computers, but simply annoy and waste the time of those who download the files.
The Cuckoo Egg Project began with Michael and Stephanie Fix. Stephanie Fix is a musician who is concerned about the illegal availability of copyrighted music through Napster. The concept centers on the idea of how a real cuckoo bird lays its eggs in another bird's nest. To the Fixes, the Napster system is like a huge nest of MP3 files, a perfect environment in which to lay cuckoo eggs
The first cuckoo egg was laid on June 10, 2000. Since then, Napster users have posted hundreds of angry messages at the Cuckoo Egg Project's Web site. Whether it's deterring them from downloading other songs has not been determined.
There is an ironic twist to the Cuckoo Egg Project. According to the official Web site's FAQ, cuckoo eggs are also not legal, because they also use unauthorized portions of copyrighted songs. But they claim that only a sample portion is used compared to the entire song being used with Napster, which is more defendable according to fair use laws. Anyone who creates and distributes MP3 files can create cuckoo eggs.