I first read about this is The Hacker's Dictionary. It contained an article about the amorphous definition of "hack" that includes this story and other classics: http://www.ccil.org/jargon/jargon_44.html
To be semantic, isn't this a crack? After all, the key to the whole scheme was breaking into the hotel rooms of the Washington U Cheerleading team. Without burgling their rooms, none of it would have happened.
I wouldn't call it 'black-hat'. While there is the aforementioned illegality (breaking in), it's a bit of a stretch to call it 'hurtful' as the only reaction was a bit of hurt pride. The stadium burst out laughing, so I wouldn't call it something that only benefitted the hackers either.
In all it wasn't a malicious act nor done for profit, so I believe that associating it with the type of hackers who do behave that way is incorrect.
I am neither a Caltech nor a MIT alumnus. Although I have never visited MIT, I have spent some time at Caltech as a visitor. When I was at Caltech, some people told me that the difference between these two schools is the mentality and maturity of the undergrad students:
MIT -> high school
Caltech -> junior high
I didn't invent the joke. I am just the messenger ;-)
About the imitation, I was more or less poking some good-natured fun at Cal-Tech, not actually calling them out. However, the Rose Bowl stuff in particular is derivative of the tradition of MIT hacks at the Harvard-Yale games that has been going on since at least 1948.
Yeah, I have heard of the Harvard-Yale game hacks. I have also heard of the tradition of putting stuff on top of the great dome. I like this Star Wars hack: