Lisa (The Cheevers) said essentially the same thing.
I attended a very good session on classroom censorship at NAEA some years
back. The presenter had a background in psychology and I believe art
therapy. While he didn't encourage these sorts of images, he recognized
some students' need to express forbidden feelings. He set up a private
corner of the room where individuals could go and do work of that sort,
with the stipulation that it could not leave the room, nor could be shown
to friends. He kept it in a special file and the student could "visit"
it. With his background, he was of course able to read the implied
message in the work and get the kid some help if necessary.
I thought this was an excellent solution and have used it myself. It
acknowledges the student's need to express something non-verbally, while
curtailing opportunities to show it off to his pals.
I wonder if hindering the students' ability to express something he can't
say out loud does more harm than good?