@marieke: nothing will happen if you use prstorm here and there, but if you are spamming the whole day, I am pretty sure, that you will be in trouble soon especially if you are in US/Europe. Maybe I am paranoid, but I think the vast number of DNS requests will make your ISP to think about you. What I do: I use a dedicated server and certainly proxies. They have no reason to complain.
And yes, it works, but you have to understand it a little. You may not use the built-in host and proxy list. You have to spam more than just only 1 request, even the shittiest web-page with only some visitors will then not list you.