I suppose I'm guilty of this, too, though I spread the FACT after actually witnessing my coworker do that.

The coworker: this guy is already known around our company for being extremely weird, but in a funny way. He's one of those odd people who are both awkward and outgoing.

The setup: Main bathroom, with three urinals. I was at the leftmost urinal, and there was nobody at the other two.

The incident: Coworker goes to the middle one, lowers his pants all the way past his knees, and starts. I GTFO of there, but see him in the mirror while washing my hands (thankfully he had a button-down shirt that covered his ass), and OH GOD, WHAT IS HE DOING?! He balls his hands up into fists and places them on his waist, then begins to gesticulate his hips side to side so that he sprays the entire urinal. It looks like he's pantomiming a sprinkler. I quickly leave before I burst out laughing.

The fallout: I get called into my VP's office later that day. I was a bit scared because I was relatively new and didn't know what the meeting could be about. When I get in, I see my roommate, who answers straight to the VP, in the office. There are also a bunch of other high level management people. I thought I was in trouble, but then my roommate says "I was just telling them about how you saw ____ in the bathroom, and they wanted to hear it from you."

I ended up being called into the office three times that day to relay the story to most of my upper management. It only gets better, because my roommate told me that the urinal guy was about to get fired for poor performance, but our VP said that he couldn't fire anybody who provided that much entertainment value to the company.

TL;DR: I saved a coworker's job by spreading a rumor about how he pees like a 5-year-old.