Specifically on this kind of stuff happening in schools/colleges/educational institutions of all sorts:
A lot of people have said that this kind of stuff is an absolute no-no in schools/colleges/educational institutions, but I know that everyone - staff included - is really proud of the pro arch in our Drama Centre. Every year, graduating drama students and the occasional graduating tech sign the back of it in the wings. I guess because it's a really strong tradition, people take it seriously enough to avoid being offensive and stuff, and there's some great art on there because of it. It's often a
bit inspirational for the kids, because you can see all the past students - some of whom have gone on to professional
theatre - and know that they were once like them. So, all up; positive thing. And I know I'll be adding my name next week before I leave the school.
On the other
hand, it's totally forbidden in our
auditorium. Probably because it's a more public space and more people use the
stage, anything more permanent than tape gets you anything from a stern word to a detention. (This means you, juniors who think it's amusing to draw phallic symbols on the music stands!). And that's fair enough, because it's a public space. If we have shows, people stick up programs and posters and sign them.
So, while I agree that it can be graffiti and rules are rules, sometimes schools are the best places for these things to stay: Inspiration is hard enough to find when you're 16, you're stuck at high school and your parents are cursing you for not wanting to take business studies at college. Let them have their little doodles - the positive ones can mean a lot.
(But paint over the phalluses.)