I have to take it off my chest.
Today, while I was working, I was searching for something in a box. I had to bend over and a door was behind me. Door opened and a woman from another department came in and pinched my butt and laughed.
I was perplex and couldn't say/do anything.
Later on I told it some good colleagues and they told me that she did it to them as well. Most of my male colleagues were touched in some inproper way by her. It's so pathetic. Even they are admitting that even if we go to HR there wouldn't be consequences. It was and is extremely disgusting.

Since there was no one else around I didn't do anything afterwards about it.