Guthrie Lonergan's artwork MySpace Intro Playlist (briefly summarized here) isn't original by any means but was done in the early '60s as mail art.
Carla Sugarman intercepted a postal sack with letters to an advice column and republished them in "Funny Mail," a widely read general circulation magazine of the day. She didn't merely retype the letters; she photographed them for reproduction as four-color offset images, with the addresses of the senders below the letters. The letters' authors meant them to be public (published correspondence in a newspaper) but not as "funny mail."
Sugarman mimeographed the "Funny Mail" article and mailed it to 300 people on her mail art mailing list. They mailed it to 300 other mail artists. Eventually the entire project was documented by John Held, Jr. and became a canonical mail art work.
The piece gained notoriety after several senders of the original letters sued Sugarman, eventually settling for a large undisclosed sum. "Funny Mail" was also joined as a defendant in the case and ceased publication shortly afterward.