Xavier,

I agree that tools like yours are useful and that 
people can abuse it. HOWEVER, if you create a 
potential dangerous tool - and as your message shows 
you are fully aware of it - you also need to accept 
responsiblity for what people are doing with it.

I would be no problem at all to build a mechanism into 
it that will read a file e.g. named httrack.txt that 
doubles the robots.txt functionality but can not be 
overwritten. Sure, people that can compile and modify 
the source won't be stopped. But in my experience, 
these are not the people abusing such tools. So you 
could at least prevent most desasters from occuring.

Rainer