I was watching the post-game show after a basketball game the other night, and seeing Magic Johnson reminded me of how surprised all of us were when we heard, while underway on USS Topeka in 1991, about how he'd been infected with HIV. Submariners won't be surprised to learn that a fairly good portion of the crew didn't believe the news until they had it confirmed when we pulled into port.
I'm not sure if they still do it (since most boats have Internet access at PD) but the only way submariners on station used to get news about the outside world was through whatever news and sports the radiomen at the transmitting stations happened to put on the broadcast. If your RMs happened to download it and print it out, you'd have some idea of what was going on in the outside world. If, however, your RMs were feeling mischievous, you'd end up with fake news that they'd attach to the regular news reports. This had happened enough that most of the Lakers fans on Topeka were convinced the RMs from the Boston area were just trying to spin them up.
While the RMs were the only ones who could really mess with fake News and Sports, other people could mess with things like regular messages. We were on station on Topeka the next year when the results of the Lieutenant promotion board came out. Since we were busy, all the unimportant traffic was being screened off our broadcast, but the SubGru we were working for sent a short message with the names of all of us who had been selected. It was an easy matter to reprint the message with the name of the one officer who was asleep deleted, and leave it on the wardroom table for him to see when he woke up. Hilarity ensued!
What's your favorite fake news/messing with messages from your time at sea?