Virus authors produce open spam relays

Hi,

just as a background information:


The german computer magazine c't and a german student of 
computer science found that authors of computer viruses are 
making business with viruses designed to turn infected computers
into open relays for spammers. One of these Viruses was found to 
install a socks proxy server (thus forming a general application
proxy), and c't could buy a list of infected machines from the virus
authors for abuse as spam relays. c't has forwarded this information
to Scotland Yard (virus author is british), and allegedly several
people have been arrested in several countries.

As a Scotland Yard officer said in an interview, they believe that
this is just the beginning and that the virus authors are currently
turning themselves into professionals.

See http://www.heise.de/newsticker/meldung/44869

Isn't that a good argument for sender verification? (I we still need 
arguments...)

regards
Hadmut