The Lucky Seven channel was likely the first pirate television station to be broadcast within the United States. It was broadcasted in Syracuse, N.Y. for three consecutive nights on April 18-21, 1978, on the unused channel 7. The broadcasters would play various films and television shows, such as "Rambo," "One Flew Over the Cuckoos Nest," "Star Trek," "Twilight Zone," and the adult film, "Deep Throat."
Between films, a man editorialized, but because he wore a gas mask, his identity goes unknown to this day. Speculation suggests that this is the work done by some students at Syracuse University, as the signal was strongest in the surrounding neighborhood.
Production is said to have been surprisingly well-done, with even a logo for the station - dice rolled to seven. A jingle was also recorded, featuring what sounded like an all-female chorus.
Because various television recorders were available at the time, there is a chance that some viewers may have recorded the incident. It is possible that the pirates may have also recorded the broadcast themselves.
The New York Times article from the era: https://news.google.com/newspapers?nid=1356&dat=19780420&id=5ZxPAAAAIBAJ&sjid=vgUEAAAAIBAJ&pg=6995,6276207&hl=en
Forum discussion of the topic: http://www.radiodiscussions.com/showthread.php?551762-quot-Lucky-Seven-quot-(Pirate-TV-Station-Syracuse-1977)