authentication problem

Hello,
When using ncsa_auth for authenticating, is it possible to
restrict a user to be surfing from more than one IP address
at the same time (or to put it more realistic: is it possible
to discourage people who have squidaccounts to spread the word) ?

I can't imagine I'm the first one with this problem, but I can't
find anything in the FAQ about it.

Greetings,
        Martin

P.S. if anyone is interested in a programma that shows this let me know
and I'll send it to you.

-- 
Tin will not rust or give in but melts directly when heated =B-)