what is the best way to crack s/w that acccess the web to check s/n?

"...it checks the s/n (which is diff on each p.c you install it on) via the web? can this be cracked or no?

I guess this is a kind of protection that we'll start to see more and more and it's obvious that nobody feels safe studying an app connected to the net. I am not sure but i remember that DAMN made some kind of "proxy"(?) to emulate some protection based on this...not sure.