Well...for a recent cancellation within 24 hours, I had to call in - since I could not separate myself from my flying partner online (he was flying eventually, I was not). Some interesting discussion ensued regarding reseating my partner out of E+. I'll spare the details here.
Suffice it to say, it is interesting what UA IT does in reaction to certain activities by its members. And what people do (even if not to game the system) is eventually noticed by UA.