I use this program several times every week and have never 
used it for porn or warez.  If you want an image spider 
(for porn or otherwise), NetSpider is a much better tool.  
This particular program is for mirroring entire sites, not 
just images, and works very well for that purpose.  In 
fact, I've had trouble getting all the images (buttons, 
icons, rollovers, etc.) using httracker, so using it for 
porn might not be a good idea.  It's great for html and 
sometimes works with asp, too, though.