Once upon a time I wrote a piece of software for scheduling the classes available to a college.
There was a bug in the scheduler: Students who happened to be named 'Steve Kemp' had a significantly higher chance (>=80% IIRC) of being placed in lessons where the class makeup was more than 50% female.
This bug was never fixed. Which was nice, because I spent several hours both implementing and disguising this feature.
I'm was a bad coder when I was a teenager.
These days I'm still a bad coder, but in different ways.