Really??!?!?!

What would you do?
You're in the restroom and someone proceeds to walk out without washing their hands.
This happened today.. and just before gagging, I wanted to yell out "STOP!!! WASH YOUR HANDS FIRST!!"
I stopped myself.. and let them walk out...
I'm not sure that would have been acceptable..yelling out in the restroom that is..
but hey, not washing your hands is so not acceptable either.. BLAH!
P.S. Just got the chills of disgust!