"A homeless man with nowhere else to go says he went back to his old high school and posed as a student for three weeks, sitting in on classes, showering in the locker room and sleeping in the theater."

Particularly interesting to me, because I was considering doing a similar thing, and it makes me wonder what kind of trouble I might get into. I've graduated from McGill now, but I'm considering going back (without registering) and just sitting in on some lectures. I know from first hand experience that "just sitting in" is a common practice at McGill, though it's usually performed by actual students of McGill, who are simply not registered in the relevant class, and not by people who are "complete outsiders". Hell, I've even sat in a few Concordia lectures. In the former case (with McGill), the professor will typically not say anything, even if he knows you're not in the class (for example, if there are only five students registered for the class, but there are six students sitting in the room). In the latter case (at Concordia), I don't think the teacher even knew or bothered counting (the difference was more along the lines of 27 registered, 28 bodies sitting).

The high school in the article is obviously in the legal right, as the 21 year old was tresspassing. McGill's campus and classrooms very probably consists of private property, so I'd be tresspassing too, but I'd expect that once I "got found out", I'd be asked to leave and/or given a warning rather than being immediately arrested. Even then, I'd be surprised if I'd ever get found out, as "outsiders" seem to wander in and out of McGill all the time. Adults wearing business suits asking for directions to certain rooms, I mean. Obviously not students or part of the faculty, so who could they be?

Anyway, I don't see anything morally wrong with just sitting in, and I think this guy just aggravated his problem by lying about being a student. Plus the fact that minors were involved might have something to do with it.