In my first couple years of professional programming, I put in a little joke for other devs and testers. The URL shown to users to update their app was stored i

In my first couple years of professional programming, I put in a little joke for other devs and testers. The URL shown to users to update their app was stored in the Windows Registry. I added some code that defaulted this value to the "Never Gonna Give You Up" video when the registry value was not set--a common condition when testing code. What I didn't realize was that deleting the registry was a common action our tech support had people try when they called in. Turns out I ended up Rick Rolling a bunch of our customers!