I remember when DS was around 7 or 8, he drew a picture of one of his classmate (not that it could be recognised as such) in a cemetary. Apparently this meant something sinister, and I actually received a phonecall from the child's mother!
I laughed it off, in a typically British way (this was in the US), but the mother failed to see the funny side, or any side other than my son having voodoo thoughts about her daughter.