Also, sometimes we (developers) like to use wacky data for testing purposes. For example, I like to put Batman as a dummy user, and my QA likes to upload cat pictures when testing uploads/images. We do it so it's obvious it's test data, and also we're lazy to think of more "real" data. Just say some users expect real(ish) data for testing. I had a client who was totally not happy when he saw Batman and Superman in th…
There was a bank that wasn’t happy with “Rich Bastard” being used as dummy data but not being replaced in the mail merge, resulting in a couple thousand of their wealthiest customers getting a mailing with the salutation “Dear Rich Bastard,” https://www.snopes.com/fact-check/dear-rich-bastard/
I was giving a demo on how to set up multiple computers in a federated setup using Active Directory, ADFS, etc... I had about 5 VMs named things like Hank, Peggy, Bobby, Boomhauer, Bill, and a test user HHill, 123 Rainy Street, Arlen, TX -- someone screenshotted and took notes during the demo and now that's in some formal training somewhere material. Thankfully, it's all internal.
When I and doing dev work and I need an available port, just any port, I use 666 -- because it's never used by anything and also DOOM. I gave a sprint demo and I used 660 instead of 666 to demo that the customer can specify the port number of screen X. Someone put that in the internal and also customer facing documentation... so now my company's product is default setup on 660, even thought it's completely user-configurable. Thank God I didn't demo with 666...