IN GENERAL, IT IS CONSIDERED EXTREMELY UNFRIENDLY TO WRITE LONG SECTIONS ALL UPCASE.
This is a widely known rule (maybe not among spammers…), and should be followed by every user that knows the netiquette.
HOWEVER, I think there is nothing wrong with spelling a word upcase now and then. Look around you; look at books, CD-ROMs, newspapers, advertisements. Do you see how much text is written upcased?
I think this is quite amusing. Look around when taking a walk in the city, and count all uppercase-only sentences. Would you have expected that much?
NP: Deftones—Digital Bath