I ran across the following sticker recently.
The English translation in smaller letters is quite alarming. It says: "please refrain from making love excessively." This seems R-Rated, and not the sort of thing a kid should have on a backpack.
But the Korean isn't really that strongly worded. What it says is "애정행각금지." A brief internet search and/or dictionary quest reveals that "애정행각" basically just means what Americans call PDA – "Public Displays of Affection." So with the "금지" tacked on, a much better (and milder) translation would be "PDA Prohibitted." This is much more G-Rated, and could even be imagined to be posted in a park or school or church. I think the point of the sticker is a little bit ironic. But with the atrocious English translation, it goes from irony to downright weird pretty quickly.