Have you ever been inside a restroom and wondered why certain signs are necessary? Take this one in our work restroom, for example: 
It leaves me wondering: Where else were people putting toilet paper? Did they use it and throw it on the floor? Surely not. Or, does this sign indicate that people were flushing other items down the loo?
And, while in Target recently, I saw another odd sign on the baby changing station. It read: Please do not leave your baby unattended. Seriously? Is that necessary? Did someone plop their kid down and then head over to the shoe section?
When I worked in an office building in Columbia, South Carolina, there was a sign in the 4th floor restroom that was not only hand written, but very hateful regarding the disposal of female sanitary products. I know people can be pigs, and cleaning up a public restroom can not be fun – but – I giggled every time I thought about the cleaning person who had one night just had it up to HERE with the mess and scribbled the threatening sign with a black marker. You know, like you did with your college roommates. (I remember writing one that said something along the lines of, “Please put dirty dishes in the DISHWASHER. IT CLEANS THEM, I DON’T.”)
Surely people who clean public restrooms are guaranteed a place in heaven.
thetightropeblog.com 
What about "employees must wash hands before returning to work"? They should wash their hands anyway.
Yes, anon – that one seems unnecessary, too!