I am not convinced that spammers are always acting 'on behalf' of XYZ
company when they are promoting a product or get-rich scheme.  Most seem to
me to be more like kids playing with (fire?) and really have no idea what
they are doing besides acting boorish.  I'm sure that XYZ company probably
isn't aware of what they are doing or if they even exist, certainly XYZ
has no expectation of exercising control over the spammer(s).
 
As for the malicious prankster types, (including enterprising students) who
spoof addresses etc, nothing you suggest is likely to faze them a bit.  It
may even make the idea more attractive...
 
 ________________________________________________________________________
 Ben Parker ............ (Oak Park IL) .......... [log in to unmask]