> However, when I tell someone not to suck my site 
> and they do it anyway, that is a direct, intentional 
> violation of my property and my rights.  

I understand your position, but here are two distinct 
problems:
- (1) intellectual propery
- (2) bandwidth and hosting limits

The (1) is not relevant for private copies (made by 
individuals, for their own private use). (2) canbe a 
problem for limited bandwidth hosting.

The vast majority of users (HTTrack or other offline 
browsers) respect websites, and use reasonnable download 
settings. Download absues can generally be discourages by 
clear warnings in the frontpage. You can alternatively 
block too aggressive downloads ; see also:
<http://www.httrack.com/html/abuse.html#WEBMASTERS>