What is with you people?

I'm tired of seeing penises drawn everywhere whenever I'm in public bathrooms. What is it with you people? The last thing I think about when going to the bathroom is whipping out a pencil (why do you have a pencil on you in the first place?) and drawing a penis on the wall. Here are my rules for when it's ok to draw penises:

1. Never draw penises.

This doesn't happen in girls' bathrooms, right? Or are there vaginas drawn everywhere?